I'm driving my sweet little 87 GT around with a bad connecting rod bearing, after only 118k on it! It over-heated in heavy traffic, because of a bad F.S. fan relay = bearing knock! :-( I can't afford to do a 3800SC swap right now, so I'm opting for the 3400 LA1 swap. I've read and am still reading the different threads on the subject, but thought I'd ask those who know the answers, a few questions as they come up, if you would be so kind...and I know you will.

Most of the swaps I've seen, on this forum, deal with using the 3.4 short-block and adapting the 2.8 cast iron heads, and stock intake manifold, etc. Wouldn't it be more prudent, and/or efficient to just use the 3.4 stock alum. heads and stock intake manifold & throttle body? That is if having the stock Fiero look is not important?! Or is there another issue involved? Performance is more important to me!

Also, I can get a LA1 engine out of a '95 Chevy Lumina APV, a 2001 Venture SUV, a 2001 Olds Silhouette SUV, a '03 Impala, and a '96 or '01 Monte Carlo. Other than low mileage, is there a preference as to which vehicle I should chose for some unknown reason to me? Also, if I do use the donor car 3.4 intake & throttle body, wouldn't it be better to use the donor car's ECM too, or does it make any difference?

I'll probably be asking more questions, as they develop, especially if I should decide to buy one of these, put it on a motor stand and start getting it ready to swap. I know I need to pull the heads, and drop the pan for inspection, and install all new Felpro gaskets; port and polish intake & exhaust manifolds, change the timing chain cover, front and rear seals, oil filter base, and relocate my starter (which is the heavier duty 3.1 starter, by-the-way) and a new water pump. I guess I also need to notch out the motor mount to facilitate the pan, per Forum thread.

Thank you in advance for your knowledgeable advice!!! I just want to get answers to these questions to make a better educated choice of which donor vehicle to use and how many more parts to include before I proceed..?

[This message has been edited by hypo327 (edited 03-20-2012).]

The aluminum heads flow much better than the cast iron heads, as does the 3400s intake manifold. The only reason to use the iron heads is to keep your engine bay looking stock.

With the choice between those years of the LA1 engine, I'd choose one of the 2001's. The intake is a bit less restrictive post 2000 models, and the intake manifold gasket is supposedly less of an issue with those later models too. Otherwise there's no difference that I know of. If you're keeping it in stock form, you can run the LA1 ECM once it's reprogrammed to get around VATs. I think if yo uwant to run the 7730, you'll need to add a compatable sensor & wheel for the timing.

quote Originally posted by Stubby79: The aluminum heads flow much better than the cast iron heads, as does the 3400s intake manifold. The only reason to use the iron heads is to keep your engine bay looking stock. With the choice between those years of the LA1 engine, I'd choose one of the 2001's. The intake is a bit less restrictive post 2000 models, and the intake manifold gasket is supposedly less of an issue with those later models too. Otherwise there's no difference that I know of. If you're keeping it in stock form, you can run the LA1 ECM once it's reprogrammed to get around VATs. I think if yo uwant to run the 7730, you'll need to add a compatable sensor & wheel for the timing.

That' s kind of what I was thinking about using the 3400 heads and manifold...makes sense to me...and it's lighter. Is there an advantage to running the donor ECM when using the 3400 intake manifold, or is the stock Fiero ECM sufficient using the 3400 fuel delivery system? I would think it depends also on the throttle body..? Hate to sound like a dummy, but what is the VAT? Is the 7730 the ECM nomenclature?

For the 3100/3400 V6 there is a 7x pick up in the middle of the block that is sent to the ICM. The ICM sends that signal to the ECM/PCM. The 7X crank pick up didn't change from when it was introduced till 2005.

So if you were so inclined to want to run a 7730 ECM the 7X crank signal that is needed is there for a 3400 engine.

Now if you are looking at an OBD2 3400, you will ALSO find a Cam sensor and high definition crank sensor (located directly behind the balancer). Both of these sensors have tails to the actual connector. A cam sensor is needed to do sequential fuel injection. The high def crank sensor gives the PCM the ability to detect misfires.

So my recommendation would be to run an OBD2 PCM running the sequential fuel injection.

---
VAT = Vehicle Anti-Theft. Most later model ECMs/PCMs in the stock configuration require a VATs signal to keep the engine running. It is part of the anti-theft equipment on the cars. To use one of these ECM/PCMs in a Fiero you can either supply a VATs signal to the ECM/PCM - OR - have the ECM/PCM reprogrammed to not need the VATs signal.

[This message has been edited by phonedawgz (edited 03-21-2012).]

You are also missing 99-04 Oldsmobile Alero and 99-05 Pontiac Grand Am from your list of donor cars... stay away from the 90s van 3400 as they have a bad upper intake manifold design. Keep 2000+ in your search. Any 3100/3400 you get, you should budget for a lower intake manifold gasket replacement, just to remove the most common failure for this engine, but I don't know why you would remove the heads unless you buy an engine with unknown compression straight out of the dirt in the yard.

The early van OBDII ECM is a good choice as it doesn't have VATS and you can send Sinister Performance the ECM to add/remove features that you may or may not have. You can also use the 7730 OBDI ECM with great results as well. Phonedawgs listed the details of the sensor needs already.

The engines that need the external trigger wheel parts are the 04+ 3500 (RPO LX9) and the 3500/3900VVT (RPO LZ4/LZE/LZ9/LZ8/LZD/LZG) engines. Very few late model 3400 (RPO LNJ) in the Chevy Equinox and Pontiac Torrent got the same ignition system as the 3500. The real difference is that the ECM directly reads the fancy LS1 style crank position sensor on the 3500/3900 engines and the coil pack is just igniters and coils, the ECM controls all aspects of the ignition system. The previous OBDII ignition has an ignition control module under the coil packs and it reads the crank position sensor and the ECM just sets advance, just like HEI reads the pickup coil on the stock Fiero distributor. So in order for these engines to use the older OBDI or II systems they need an external 7X crank sensor.

Check out the pushrod section on 60DegreeV6.com and WOT Tech if you really want to get your check wallet light working.

[This message has been edited by carbon (edited 03-21-2012).]

But if you are going to send your PCM to someone to have it programmed, then the programmer will turn off the VATs. Therefore it doesn't make any difference if the PCM had VATs in the original vehicle.

Also to be clear - If you are starting with an OBD2 engine with the cam and high def crank sensor, and you are going to have a third party program your ECM/PCM, then there is no logical reason to downgrade to the 7730 OBD1 ECM.

The reasons that you might want to run a 7730 ECM are that you want to do the programming yourself, and you already have the equipment to program the 7730, or your engine does not have the sensors needed to run the OBD2 PCM. The 7730 ECM fits in the stock location better, however with some arm rest modifications any ECM/PCM will fit with the exception of the 96/97 PCMs.

**Or maybe you just want to run the 7730 ECM so you can use my new USB to OBD1 ALDL direct cable to monitor your engines operation!!!**

** Shameless self promotion **

https://www.fiero.nl/forum/Forum4/HTML/061099.html

[This message has been edited by phonedawgz (edited 03-21-2012).]

Shameless self promotion would be a problem if your stuff/services sucked... but they don't.

Hello,

A couple things on the starter. The 3400 (LA1) has the starter on the correct side of the block so it doesn't need to be relocated as the 3.4L F-body motors require. If possible keep the starter that came on the 3400. These starters are light and powerful. You may have to get a shim to space it out but they're cheap and at every parts store. The 3.1L starter you have could be the same but if it looks 2x bigger it's 2x worse not better.

~sam

If memory serves me right, do not use a 2003+ PCM. Something about them being harder to deal with for the programmer. Everyone else seems to have covered the basics. Good luck and don't be afraid to ask questions.

quote Originally posted by phonedawgz: But if you are going to send your PCM to someone to have it programmed, then the programmer will turn off the VATs. Therefore it doesn't make any difference if the PCM had VATs in the original vehicle. Also to be clear - If you are starting with an OBD2 engine with the cam and high def crank sensor, and you are going to have a third party program your ECM/PCM, then there is no logical reason to downgrade to the 7730 OBD1 ECM. The reasons that you might want to run a 7730 ECM are that you want to do the programming yourself, and you already have the equipment to program the 7730, or your engine does not have the sensors needed to run the OBD2 PCM. The 7730 ECM fits in the stock location better, however with some arm rest modifications any ECM/PCM will fit with the exception of the 96/97 PCMs. **Or maybe you just want to run the 7730 ECM so you can use my new USB to OBD1 ALDL direct cable to monitor your engines operation!!!** ** Shameless self promotion ** https://www.fiero.nl/forum/Forum4/HTML/061099.html

I don't know what a OBD1 and OBD2 are and the difference between and ECM an a PCM is..? Apologize for my ignorance...

Thanks so much for all you guys enthusiastic advice, but when you hit me with nomenclature that I'm not familiar with, it's hard for me to know exactly what you're are talking about without referencing tech manuals that I don't have, and it kinda makes an old man's brain hurt. I'm an old 60's & 70's novice engine builder, and built a few really hot engines for the time, but these new computerized electronics really make my brain spin! So maybe if you can be a little more explanatory for an old fart that can barely operate his home computer, and cell phone...? LOL...hope you don't mind! :-) After the mid 70's I didn't get much closer to my cars than general maintenance, and overhaul a naturally aspirated carburetor on my older (non computerized) cars. I was to busy designing buildings! my 87 Fiero is the most modern car I have attempted to work on, and I'm still in big-time learning mode. So now that you know, somewhat, how ignorant I am, I hope you still want to help educate me. I'm actually looking forward to putting that engine on a stand and start tearing it down. So, I guess I better back-up and tell you what I have planned for my engine build.

The engines I listed above are engines available out of cars in a salvage yard. A very nice one, I might add, across the border in Chilliwack, B.C.. If you go on line to pickapart.ca you can pull-up any car I'm referencing. I can buy any engine on the lot for $89.95, use their large engine pulling stands on car wheels, and roll the engine over my pick-up bed and set it in. When I get it home, I have 90-days to return it for another engine for any reason. Needless to say, I'm going to go completely through it for a total rebuild, and it should be fun! The mechanics aren't any different than in my day, when worked on my hypo 327 (hence my handle). I know I can do this with your help...just remember to keep it simple and specific as possible for a novice on modern computerized cars.

Having said all that, you should have a better idea on who you are tutoring. Hopefully when I'm done, I'll have learned something..? I plan to take my time and have some fun. First I want you guys to help me select the right vehicle engine. My main criteria right now is find a vehicle that looks like it's been well maintained, clean, and as low mileage as possible.

My son and I made our first trip to Pick-a-Part salvage yard today. We drooled over some nice 3800SC's an 3.4 DOHC engines, then started looking for a good 3400. They have lots of poorly maintained and/or ones that are torn apart to much. we did find some good looking ones though. The two best we found today were in a 2001 Chevy Monte Carlo, and a very clean '97 Chevy Venture SUV, with 145k miles. One of you guys said to stay away for anything below year 2000 due to the intake manifold issue, although I liked that manifold because it didn't have raised engine type on the top, where I could put a Fiero decal. We are going back to take a look at some Grand Am's that we didn't get to yet. My research says the Grand Am's are 170 hp or 10 hp less than the SUV's at 180 hp. They don't have any Cameros or Firebirds, but my research says they are 160 hp or 20 hp less than the SUV's and the one Monte Carlo. I Would like to know what the difference is attributed to, if it's just the difference in the fuel handling (throttle bodies, injectors and/or intake manifolds) or what? That's one of the reasons I kinda want to go with one of the 180 hp units...Is that legitimate? I just want to get the most bang for my buck, among LA1 3400 engines!

After listening to all you guy's comments above, can I just NOT use all those special sensors, above and beyond what I need for my Fiero, and use my stock Fiero ECM, and keep it simple? I noticed Randy Enerson just blocked off or plugged some sensor locations in his build, but then he used the Fiero intake manifold set-up. Can I use the stock 3400 intake manifold and throttle body, and still use my stock Fiero ECM? It sure would be allot easier! I want to keep the electronics as simple and as close as possible to the simpler stock Fiero set-up, but if I have to use the stock 3400's ECM, I need to know, so I can pull it at the salvage yard. I had asked this question initially, but I probably wasn't specific enough...?

[This message has been edited by hypo327 (edited 03-22-2012).]

quote Originally posted by hypo327: I don't know why my reply ended up in that format? Guess I did something wrong, but don't know what...never had that happen before. Sorry!

You put your reply inside the quote tags... there is an edit button if you want to go back and correct it. Just look for the [/QUOTE] tag and cut and paste back up to the end of phonedawgs post.

GM started calling the ECM the PCM when it started controlling more than just torque converter lock up.

The Fiero's ECM is quite archaic compared to the 3100/3400. Maybe with quite a bit of modification it could be made to run 3100/3400, but it would be as much if not more work than putting in the 3400 PCM.

If you are going to make a harness so you can run a 7730, why not just make it for the OBD2 3400 PCM? There are only two more connectors (CKP, CMP).

quote Originally posted by phonedawgz: GM started calling the ECM the PCM when it started controlling more than just torque converter lock up. The Fiero's ECM is quite archaic compared to the 3100/3400. Maybe with quite a bit of modification it could be made to run 3100/3400, but it would be as much if not more work than putting in the 3400 PCM. If you are going to make a harness so you can run a 7730, why not just make it for the OBD2 3400 PCM? There are only two more connectors (CKP, CMP).

And MAF...

OBD or On Board Diagnostics is broken up into basically two categories pre-96 (I) and post 96 (II). There are some grey areas around 94-95 but for what you're doing it shouldn't come up. As such the Fiero ECM is OBDI. The 7730 computer came out later in several cars is much faster and is a popular upgrade to the Fiero computer but is still OBDI. I went with this computer because it was cheaper and the source code is 100% decoded. If you're not going to be messing around with your own tune OBDII may not be much more money. According to popular legend all LA1 engines are physically the same, only the exhaust and tuning affect their power. Since you'll be doing the exhaust and tune anyway there's no reason to look for the higher stock hp version.

~sam

I've been looking at doing a 3x00 swap at some point (when I have the cash....) It would definately be nice if there were a few more build threads avaiable on the subject. From what I have found the big reason to use the iron heads is so that you can use the fiero intake, water pump, accessories and dogbone mount. With the aluminum heads you will need to figure out a replacement for the dog bone, the coolant system hoses, AC hoses, and intake ducting.

For the intake I used 2 3400 intake hoses, a $3 PVC adapter from home depot, a pipe plug, and hose clamp. It's an easy workable solution that cost me <$20 and looks pretty stock. Also if I ever lose an intake air temp sensor I have 2 spares already in place.

I've been meaning to do a writeup on this swap for about 6 months but I'm only about half way to a 1rst draft. Hopefully I'll get the rest of the pictures I need this weekend. Unfortunately I don't mess with A/C so you won't be able to copy that from me. I'm not all that happy with my dog-bone setup but I want to try what I have in mind 1rst.

~sam

Yeah... the Fiero is technically pre-OBD. The 85 Fiero 2.8 was the first MPFI 60* V6... before that it was carbs and TBI.

quote Originally posted by hypo327: They don't have any Cameros or Firebirds, but my research says they are 160 hp or 20 hp less than the SUV's and the one Monte Carlo. I Would like to know what the difference is attributed to, if it's just the difference in the fuel handling (throttle bodies, injectors and/or intake manifolds) or what? That's one of the reasons I kinda want to go with one of the 180 hp units...Is that legitimate? I just want to get the most bang for my buck, among LA1 3400 engines!

Just to make sure you understand, the Camaro and Firebirds did not come with an LA1 (3400), it is an iron head 3.4 that is more similar to our Fiero 2.8.

About the upper intakes, the blank one (which I am actually using on my 3400 right now just because it looks the best, with a "Fiero" sticker mind you , is actually one of the worst flowing intakes you can use. The later year with "3400SFI" cast on the top flows the best/most even, you can always grind off the numbers if being backwards bothers you (it bothers me haha).

Using the Fiero top end is a huge step backwards but it will definitely make the electronics easier. Don't expect to get the rated 170 horsepower out of it that way though unless you really work the intake, heads, and exhaust over (plus a good tune).

For ease of swap (starting with a 2.8 Fiero), easiest would be a camaro/firebird 3.4 with fiero top end. Basically a block swap. Then the next step up is the 3100/3400 because it basically bolts right up and the most difficult part being the new wiring (but it isn't that hard using the diagrams from Sinister Performance and with all the help here on the forums).

You can pick any 3400 you find (though the one from an Equinox is more difficult) it's just suggested to find a 2000+ and you can run it with any 3100/3400 PCM (but suggest 98-01) For example, my 2005 Equinox engine is being run with a 98 Monte Carlo computer and wiring harness, even though it's from a 3100.

I hope I'm making sense, I feel like I'm rambling now...

quote Originally posted by KaijuSenso: Just to make sure you understand, the Camaro and Firebirds did not come with an LA1 (3400), it is an iron head 3.4 that is more similar to our Fiero 2.8. About the upper intakes, the blank one (which I am actually using on my 3400 right now just because it looks the best, with a "Fiero" sticker mind you , is actually one of the worst flowing intakes you can use. The later year with "3400SFI" cast on the top flows the best/most even, you can always grind off the numbers if being backwards bothers you (it bothers me haha). Using the Fiero top end is a huge step backwards but it will definitely make the electronics easier. Don't expect to get the rated 170 horsepower out of it that way though unless you really work the intake, heads, and exhaust over (plus a good tune). For ease of swap (starting with a 2.8 Fiero), easiest would be a camaro/firebird 3.4 with fiero top end. Basically a block swap. Then the next step up is the 3100/3400 because it basically bolts right up and the most difficult part being the new wiring (but it isn't that hard using the diagrams from Sinister Performance and with all the help here on the forums). You can pick any 3400 you find (though the one from an Equinox is more difficult) it's just suggested to find a 2000+ and you can run it with any 3100/3400 PCM (but suggest 98-01) For example, my 2005 Equinox engine is being run with a 98 Monte Carlo computer and wiring harness, even though it's from a 3100. I hope I'm making sense, I feel like I'm rambling now...

No, you make perfect sense, and your suggestions go right along with the others who have been helping me. I've pretty much abandoned the Idea of using the really clean '97 Chevy Venture I found, and am leaning more toward the '2001 Monte Carlo, which is very clean also. What I mean by clean, is there is no sign of engine blow-by build up on the valve cover and engine top, and looking into the valve cover, the engine looks exceptionally clean. Before I remove the engine from the donor, I'm going to remove the valve cover to get an Idea of just how clean it has been. I haven't decided on the Monte Carlo yet though, until I'm able to look at the 2002 Grand Ams on the lot. These are all rated 170 hp. and being FWD cars should be easier swaps. There is one Grand Am that is a 3.1 and has a Getrag 5-sp. Will that that Getrag bolt-up to a 3.4 engine, or does it have a completely different bolt pattern?

When I decide on an engine, whether it's from the Monte Carlo, or one of the 3.4 Grand Am's , I'll be on line to ask you all specifically what what I should do with my overhaul and swap. No matter what I get, I'm going to pull the PCM (see I'm learning something) and the wiring harness, etc. On-ward and upward...I hope!

Just to let you know. I picked up a brand new 1-ton cherry picker (engine puller), and a engine stand from Harbor Freight today, for a total of $219.98, just finished assembling them, and they look great. My son and I are going to Chilliwack, BC either tomorrow, or Friday to get an engine! I'm still leaning toward the Monte Carlo at this time, but I'll let you know when I get it. As far as bolting it to the engine stand, I just need bolts the size that fit the block and long enough to go through the engine stand bolt tubes and allow for enough thread to screw into the block...right? 2.5" or 3"...which one? The engine stand backer plate and bolt shaft measure exactly 2".

quote Originally posted by Justin_J: No, you make perfect sense, and your suggestions go right along with the others who have been helping me. I've pretty much abandoned the Idea of using the really clean '97 Chevy Venture I found, and am leaning more toward the '2001 Monte Carlo, which is very clean also. What I mean by clean, is there is no sign of engine blow-by build up on the valve cover and engine top, and looking into the valve cover, the engine looks exceptionally clean. Before I remove the engine from the donor, I'm going to remove the valve cover to get an Idea of just how clean it has been. I haven't decided on the Monte Carlo yet though, until I'm able to look at the 2002 Grand Ams on the lot. These are all rated 170 hp. and being FWD cars should be easier swaps. There is one Grand Am that is a 3.1 and has a Getrag 5-sp. Will that that Getrag bolt-up to a 3.4 engine, or does it have a completely different bolt pattern? When I decide on an engine, whether it's from the Monte Carlo, or one of the 3.4 Grand Am's , I'll be on line to ask you all specifically what what I should do with my overhaul and swap. No matter what I get, I'm going to pull the PCM (see I'm learning something) and the wiring harness, etc. On-ward and upward...I hope! Just to let you know. I picked up a brand new 1-ton cherry picker (engine puller), and a engine stand from Harbor Freight today, for a total of $219.98, just finished assembling them, and they look great. My son and I are going to Chilliwack, BC either tomorrow, or Friday to get an engine! I'm still leaning toward the Monte Carlo at this time, but I'll let you know when I get it. As far as bolting it to the engine stand, I just need bolts the size that fit the block and long enough to go through the engine stand bolt tubes and allow for enough thread to screw into the block...right? 2.5" or 3"...which one? The engine stand backer plate and bolt shaft measure exactly 2".

LOL, I didn't realize my son, Justin_J, left his account up on my computer, so I responded in his name, thinking it was my account! The quote above is actually from me, (hypo327).

[This message has been edited by hypo327 (edited 03-22-2012).]

I'd also be interested in finding out how the engine mounting would work. and what type of clutch would be needed.

and what about the plumbing (ie...fuel, coolant, etc)

eventually I want to have a 3400 or 3500 engine in my fiero (long time down the road considering I'm completely rebuilding my 3.4L F-body engine right now.

but it's always good to learn new things

quote Originally posted by gtxbullet: I'd also be interested in finding out how the engine mounting would work. and what type of clutch would be needed.

Mounting is the easy part. The 3400 bolts right to the tranny using an 88GT flywheel and clutch. For the engine mount, you use a stock 85-87 V6 bracket and shave it down a little to clear the oil pan on the 3400. You do need a cast clutch arm...the stamped ones are longer and will hit the exhaust crossover. Some pics can be seen here: https://www.fiero.nl/forum/Forum1/HTML/082086.html

quote Originally posted by gtxbullet: and what about the plumbing (ie...fuel, coolant, etc)

Ask me this part again in a couple weeks. It doesn't look like it will be too difficult though. Work has picked back up on this project after a year of delays. Just for reasons of comparison of projects....we are using a 2005 LA1 from a Chevy Venture, PCM from a 1998 Venture (Tuned by Sinister Performance), Isuzu 5 speed tranny, and this is being dropped into an 85 GT.

Couple notes on years of the engine...in theory, all LA1s are the same. Just like in theory all L44s were the same. But most of us know that there WERE improvements over the years in the stock Fiero engines. The one thing that comes to mind is the better oiling on the 86+ compared to the 85. Slight improvements like this happened on the LA1 also, meaning the later years are going to be better. The LA1s from the SUVs (Torrent and Equinox) were different. I forget what the exact differences were...but they were big enough to make me avoid that route.

Talk to the person that is going to tune your PCM before you get one. I spoke with Ryan (Sinister Performance) first, and he suggested I go with the 1998 PCM simply because the wiring had already been sorted out for it. PM me if you need a copy of wiring diagrams (I admit it, I am too lazy to pull them up right now).

[This message has been edited by CowsPatoot (edited 03-22-2012).]

First off, to make sure everybody is talking about the same motor, refer the motor as it's nomally called, GM made three engine that have a 3.4L displacment. First one would be the F-body (camaro/ firebird) known as 3.4L with iron heads. Second one is the 3.4L DOHC (dual over head cam) found in mid 90's Grand Prix's/ Lumina's. Then you have the 3400 which is a FWD engine. I'm not trying to be rude, but I've seen alot of confusion on the board when members get the motors mixed up.


If you want to do a 3400, first thing you should be thinking about is if you want to run OBD1 or OBD2. The stock fiero ECM will not be able to run this motor in a stock set-up. If you want to keep it a simple swap, I'd suggest looking for an F-body 3.4L & put the fiero top end on it.

After deciding the 3400's computer choice, decide which method of accessory drives you want on it. I've done three 3400 swaps so far and rebuilt the first one a couple of times with upgrades. My preference is to use the stock 3400 system, but we have built one using the stock Fiero timing cover, water pump & accessories.

If you plan on using a manual, an 88 V6 flywheel will be needed. If you go into www.car-part.com & do a search, it will come up with other vehicles that use the same flywheel. GM's 2.2L J-bodies I believe used the same flywheel, that's where I got mine from. Do not use a stock clutch, at first it will hold while you baby the car till it breaks in, after that it's gone in a year. I've done welll with a dual friction centerforce but that's almost gone after 5 years, next will be a Spec stage 2+ or 3 for me.

Front engine mount will need minor modding, 84-87 will use a V6 "L" bracket which will need the "hump" grinded off and the motors oil pan will need triming. It is cast and there is an empty cavaity that will be shaved off the corner. With 88s, most of the bracket lines up except for one hole from what I've read (no experience with them)

I really suggest you get rodney dickmans poly engine mounts, I've torn apart to sets of new stock rubbers and broken one tranny bracket. I've since gone with Rodneys tranny brackets too.

My Alternator sits in the location of the A/C, I don't use the stock alternator, I use a C130 (88 style) which mounts to an A/C compressor bracket from an early 3100 series motor. The upper dog bone section is cut off and minor mods to the bracket for alternator clearance. Once you have this bracket, bring it and an alternatpr to a rebuild shop to size up. A new outer shell will be needed, there are three different sizes with bolt holes 180* apart, the 88 fiero is the smallest size, you need the middle size. Also need a new pulley, mines an 7 groove from a mustang (SC) it's needed to stick out farther then normal to line up with the crank pulley.

Power steering pump will be deleted, remove the grooved pulley from the tensioner, a spacer will be needed to install it in the location of the power steering pump. The smooth pulley will then be attached to the tensioner and installed in the lower location normally found on GM 3.1L cavaliers (88-94) new belt will be needed.

Make sure you get the exhuast downpipe or at least a foot of it, you will need the flange from it to build you custom exhaust.

My upper dogbone is made up from three different brackets welded together. I use the rear section from a V6 dog bone brace, the front section cut off from a 4 cylinder bracket, and the 3400 bracket which bolts the the cylinder head. Takes and afternoon with trial fits to build one, but it hasn't failed on two swaps yet.

Coolant lines: if you are 87/88 the heater core return line is in the main under the car, so only one line out is needed and it's located under the throttle body. The return line if needed (pre 87) is the feed line for the throttle body heater. Both lines come back to the trunk wall. Since mines an 87, I deleted the throttle body heater line at the source over the water pump & capped it off with a bleed valve/ refill station.

If you plan on using the stock fiero timing cover, a couple of holes need to be plugged on it. you wil run you most of your lines like the 2.8L except for the feed line for the heater core.

Throttle cable will need adapting to the new throttle body, this has always been done differently on all my swaps. Some 87/88 4 cylinder cables seem to be able to just fit the bracket, V6's need to be modded.

DO NOT use the stock Fiero air canister with the 3400 motor, it will STARVE for air. When I did my first swap, I put a cold air system in and the car dynoed at 175 WHP. Last year the same motor was rebuilt with a regrind cam, ported intake & exhaust, then put into another Fiero which had the stock air canister on it. The car dyno'd 160 WHP same cam was used in a friend 3400 j-body swap and he got 200 WHP out of it. I put the cold air intake on and you could feel the difference. I never got back to the dyno shop though. Now I'm working on a 3500 plenum swap for it.

Harness: If you're great with wires and can easily read schematics, shouldn't be hard to build your own. I'm an electrician by trade, my hobby is mechanics so it was a no brainer for me to build. I went OBD1 since a friend of mine did my initial programming for me. We've since started using another forum members tune which is really reliable and no issuses with (Scott999) I believe is his name. There are a couple on the forum that build & sell harness's for the 3400 swap. The harness I prefer to use is a V6 automatic (with A/C if available) Has the most lines in it to work with when rebuilding one for the 3400 swap. 4 cylinder harness doesn't have the same ECM pin connectors as the 7730 ECM so they require a lot more work & soldering. Make sure your get all the connectors for the 3400 motor since they will need to be splced into the harness.

For you exhuast, if you can get away without having a cat on your car, you are sooooo lucky. It's the law in Ontario to have one on my car so it's very tight fitting. Mine is probably 3 feet long total, would be 2 feet if i didn't need a cat. Come directly out of the flange and bends right into the cat. Outt of the cat into another flange (for remoaval purposes) then into the stock muffler. I'm running 2.5" cat, which is tight, 2.25" is a better fit.

For your gas lines, I would not suggest turning the rail 180*, you would have to pinch the cross over line to get the plenum to fit properly unless you have spacers made to raise the plemun. I routed my gas lines the same way 84-86 4 cylinders have them with the exception of mounting the fuel filter on the lower frame rail. My stock V6 fuel pump worked well with the stock 3400 set-up, I've since upgraded to an 88 corvette fuel pump with the extra work done to the motor.

OBD1 ECM used is a 7730 which is found on any gm 3.1L multiport engine, the ecm holder if from any 87/88 fiero with a 4 cylinder engine which has the side plugs on the ECM rather then on the bottom.

There's probably more that I can't even think of right now which I've done, I know one day i would like to try an build an OBD2 harness for my own purposes and programming with HP tuners, but not in my udget right now.

Here's a link to picture of the swaps I've done. I still need to load up pics from version 2 which uses the stock Fiero front cover. I'll see I can do that now before i go to bed, spent too long writing this out trying to think of what i've done in each swap.

http://s913.photobucket.com...ums/ac339/3400Swaps/

------------------

Currently own: 87 GT 3400, 87 SE, 87 Coupe T-top
Previously owned: 84 Sport Coupe, 2 85GT's, 87 Coupe (T-top donor)
G.T. Fieros

From Darth Fiero's web site

How to wire up a 1998-1999 3100 or 3400 V6 OBD-2 PCM using a 4T60-E or manual transmission into your Fiero
Works with PCM service numbers:
16236757
09356741
09357034
09361735
09374997
09378702
09380717
12209614
12209624
http://www.gmtuners.com/fil...400_4T60E_wiring.pdf

How to wire up a 1999-up 3100 or 3400 V6 OBD-2 PCM using a 4T65-E transmission into your Fiero
Works with PCM service numbers:
16236757
09356741
09357034
09361735
09374997
09378702
09380717
12209614
12209624
http://www.gmtuners.com/fil...400_4T65E_wiring.pdf

---
Shameless self promotion

If you plan on having someone make your harness
http://reddevilriver.com
*14 day turn around from receiving a completed build sheet and down payment.

When I build a 3x00 harness I keep the injector sub harness disconnect. The CTS gets dropped off of the injector sub harness however since it needs to be converted to a 3 pin type. No additional charge for AC or Automatic Transmission. No additional charge for OBD2. (OBD2 suggested)

quote Originally posted by CowsPatoot: The LA1s from the SUVs (Torrent and Equinox) were different. I forget what the exact differences were...but they were big enough to make me avoid that route.

Just to be clear, the Equinox/Torrent 3400 is coded LNJ, and has more in common with the 3500. Here is a link to my build thread if anyone is interested

https://www.fiero.nl/forum/Forum2/HTML/111290.html

and here is a link to a very nice part by part example of the differences between the LA1, LNJ, and both 3500 and 3900 variants. Make sure to read as a PDF so you get all the nice pictures!

http://www.enginebuildermag...y_34l35l_engine.aspx

And x-thumpr-x has written one of the best explanations of this swap I've seen to date.

Remebered two other parts right now that I used. When building for OBD1, the knock sensor needed will be from a GM 3.1L (88-94). The Coolant Temperature Sensor/sendor (CTS) was used from a ealy 90's sunbird with 2.0L motor. This unit has three terminals on it, one for the temperature gauge, the other two are for the ECM. Stock Fiero's have two sensors/ sendors on the motor, one is for the ECM, the other goes to the temperature gauge & temp idiot light. You loose the idiot light wire when you do this swap, but the light will still be used. The 3400 has a low oil sensor on the bottom of the oil pan, I have this wired directly to the temperature idiot light in the guages.

I've always wanted to make up a website showing what's involved with doing this swap, but procrastination always gets the better of me.

Hypo, if you're going to swap in an LA1 3400 V6, then I recommend you use an OBD2 PCM with the swap so you can keep the SFI working on the engine. The 1227730 isn't SFI-capable, and is actually more difficult to tune (when using one of these engines) than an OBD2 PCM (although OBD2 tuning software is a bit more expensive). There is an SFI-capable OBD1 PCM you could use instead, but the amount of wiring work required wouldn't be much different than just using the OBD2 PCM and the OBD2 PCM would be the best thing to use with an LA1 3400 V6 in a Fiero swap.

As was mentioned previously in this thread, I have wiring instructions available on my website for an LA1 3400 swap using an OBD2 PCM. I also do custom programming for these PCMs as well (as do others on here). I would recommend staying away from 2001-newer programming based on the fact it has some nasty emissions diagnostics that like to run that aren't easy to disable. You can use up to 2000 model year programming without running into this issue and up to this model year covers just about any transmission you'll be using (manual, 4T40/4T45-E, 4T60-E, or 4T65-E).

NOTE: The 3400 LNJ engine is different and will not directly work with an "older" OBD2 PCM that was set up to run an LA1 3400. You'd need some custom parts to make the LNJ engine work with an LA1 PCM or earlier OBD1 ECM as KaijuSenso mentions in his info/build threads.

-ryan

------------------
OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

[This message has been edited by Darth Fiero (edited 03-23-2012).]

quote Originally posted by x-thumpr-x: First off, to make sure everybody is talking about the same motor, refer the motor as it's nomally called, GM made three engine that have a 3.4L displacment. First one would be the F-body (camaro/ firebird) known as 3.4L with iron heads. Second one is the 3.4L DOHC (dual over head cam) found in mid 90's Grand Prix's/ Lumina's. Then you have the 3400 which is a FWD engine. I'm not trying to be rude, but I've seen alot of confusion on the board when members get the motors mixed up. If you want to do a 3400, first thing you should be thinking about is if you want to run OBD1 or OBD2. The stock fiero ECM will not be able to run this motor in a stock set-up. If you want to keep it a simple swap, I'd suggest looking for an F-body 3.4L & put the fiero top end on it. After deciding the 3400's computer choice, decide which method of accessory drives you want on it. I've done three 3400 swaps so far and rebuilt the first one a couple of times with upgrades. My preference is to use the stock 3400 system, but we have built one using the stock Fiero timing cover, water pump & accessories. If you plan on using a manual, an 88 V6 flywheel will be needed. If you go into www.car-part.com & do a search, it will come up with other vehicles that use the same flywheel. GM's 2.2L J-bodies I believe used the same flywheel, that's where I got mine from. Do not use a stock clutch, at first it will hold while you baby the car till it breaks in, after that it's gone in a year. I've done welll with a dual friction centerforce but that's almost gone after 5 years, next will be a Spec stage 2+ or 3 for me. Front engine mount will need minor modding, 84-87 will use a V6 "L" bracket which will need the "hump" grinded off and the motors oil pan will need triming. It is cast and there is an empty cavaity that will be shaved off the corner. With 88s, most of the bracket lines up except for one hole from what I've read (no experience with them) I really suggest you get rodney dickmans poly engine mounts, I've torn apart to sets of new stock rubbers and broken one tranny bracket. I've since gone with Rodneys tranny brackets too. My Alternator sits in the location of the A/C, I don't use the stock alternator, I use a C130 (88 style) which mounts to an A/C compressor bracket from an early 3100 series motor. The upper dog bone section is cut off and minor mods to the bracket for alternator clearance. Once you have this bracket, bring it and an alternatpr to a rebuild shop to size up. A new outer shell will be needed, there are three different sizes with bolt holes 180* apart, the 88 fiero is the smallest size, you need the middle size. Also need a new pulley, mines an 7 groove from a mustang (SC) it's needed to stick out farther then normal to line up with the crank pulley. Power steering pump will be deleted, remove the grooved pulley from the tensioner, a spacer will be needed to install it in the location of the power steering pump. The smooth pulley will then be attached to the tensioner and installed in the lower location normally found on GM 3.1L cavaliers (88-94) new belt will be needed. Make sure you get the exhuast downpipe or at least a foot of it, you will need the flange from it to build you custom exhaust. My upper dogbone is made up from three different brackets welded together. I use the rear section from a V6 dog bone brace, the front section cut off from a 4 cylinder bracket, and the 3400 bracket which bolts the the cylinder head. Takes and afternoon with trial fits to build one, but it hasn't failed on two swaps yet. Coolant lines: if you are 87/88 the heater core return line is in the main under the car, so only one line out is needed and it's located under the throttle body. The return line if needed (pre 87) is the feed line for the throttle body heater. Both lines come back to the trunk wall. Since mines an 87, I deleted the throttle body heater line at the source over the water pump & capped it off with a bleed valve/ refill station. If you plan on using the stock fiero timing cover, a couple of holes need to be plugged on it. you wil run you most of your lines like the 2.8L except for the feed line for the heater core. Throttle cable will need adapting to the new throttle body, this has always been done differently on all my swaps. Some 87/88 4 cylinder cables seem to be able to just fit the bracket, V6's need to be modded. DO NOT use the stock Fiero air canister with the 3400 motor, it will STARVE for air. When I did my first swap, I put a cold air system in and the car dynoed at 175 WHP. Last year the same motor was rebuilt with a regrind cam, ported intake & exhaust, then put into another Fiero which had the stock air canister on it. The car dyno'd 160 WHP same cam was used in a friend 3400 j-body swap and he got 200 WHP out of it. I put the cold air intake on and you could feel the difference. I never got back to the dyno shop though. Now I'm working on a 3500 plenum swap for it. Harness: If you're great with wires and can easily read schematics, shouldn't be hard to build your own. I'm an electrician by trade, my hobby is mechanics so it was a no brainer for me to build. I went OBD1 since a friend of mine did my initial programming for me. We've since started using another forum members tune which is really reliable and no issuses with (Scott999) I believe is his name. There are a couple on the forum that build & sell harness's for the 3400 swap. The harness I prefer to use is a V6 automatic (with A/C if available) Has the most lines in it to work with when rebuilding one for the 3400 swap. 4 cylinder harness doesn't have the same ECM pin connectors as the 7730 ECM so they require a lot more work & soldering. Make sure your get all the connectors for the 3400 motor since they will need to be splced into the harness. For you exhuast, if you can get away without having a cat on your car, you are sooooo lucky. It's the law in Ontario to have one on my car so it's very tight fitting. Mine is probably 3 feet long total, would be 2 feet if i didn't need a cat. Come directly out of the flange and bends right into the cat. Outt of the cat into another flange (for remoaval purposes) then into the stock muffler. I'm running 2.5" cat, which is tight, 2.25" is a better fit. For your gas lines, I would not suggest turning the rail 180*, you would have to pinch the cross over line to get the plenum to fit properly unless you have spacers made to raise the plemun. I routed my gas lines the same way 84-86 4 cylinders have them with the exception of mounting the fuel filter on the lower frame rail. My stock V6 fuel pump worked well with the stock 3400 set-up, I've since upgraded to an 88 corvette fuel pump with the extra work done to the motor. OBD1 ECM used is a 7730 which is found on any gm 3.1L multiport engine, the ecm holder if from any 87/88 fiero with a 4 cylinder engine which has the side plugs on the ECM rather then on the bottom. There's probably more that I can't even think of right now which I've done, I know one day i would like to try an build an OBD2 harness for my own purposes and programming with HP tuners, but not in my udget right now. Here's a link to picture of the swaps I've done. I still need to load up pics from version 2 which uses the stock Fiero front cover. I'll see I can do that now before i go to bed, spent too long writing this out trying to think of what i've done in each swap. http://s913.photobucket.com...ums/ac339/3400Swaps/

Thank you so much for the exellent outline, describing very clearly what I'm trying to find out. Based on everyone's information on this thread, I do believe I want to stay away from the third generation 3400's, because it would be more complicated than I want to get, and cost more money than I want to put into it. If I was going to get that involved, I'd go with the 3800SC, but I need to keep it simple and keep the cost down. So I'm probably going to go with the Generation III, 1993 - 1995 Camaro or Firebird 3.4L L32 long block and use my Fiero upper fuel delivery system, like most every one else doing a 3.4 swap. Pick-a-part salvage in Chilliwack, B.C. only has one 3.4L in a '95 Firebird, They are scarce, so I hope it's in decent shape! I'm not going up there until Wednesday this next week, so I'll keep ya'll posted.

They do have another 1990 Firebird with a 3.1L mfi, so I'm assuming it is the Gen II McLaren Turbo that cranks out 205 h.p. Is that turbo something worth adapting to the Fiero, or is it even practical?

IIRC, the 1990 Firebird came with the 3.1 MFI V6 as an option, but it was not turbocharged.

The only vehicle to get the turbo 3.1 was the Grand Prix and only for one year.

quote Originally posted by KaijuSenso: Just to make sure you understand, the Camaro and Firebirds did not come with an LA1 (3400), it is an iron head 3.4 that is more similar to our Fiero 2.8. About the upper intakes, the blank one (which I am actually using on my 3400 right now just because it looks the best, with a "Fiero" sticker mind you , is actually one of the worst flowing intakes you can use. The later year with "3400SFI" cast on the top flows the best/most even, you can always grind off the numbers if being backwards bothers you (it bothers me haha). Using the Fiero top end is a huge step backwards but it will definitely make the electronics easier. Don't expect to get the rated 170 horsepower out of it that way though unless you really work the intake, heads, and exhaust over (plus a good tune). For ease of swap (starting with a 2.8 Fiero), easiest would be a camaro/firebird 3.4 with fiero top end. Basically a block swap. Then the next step up is the 3100/3400 because it basically bolts right up and the most difficult part being the new wiring (but it isn't that hard using the diagrams from Sinister Performance and with all the help here on the forums). You can pick any 3400 you find (though the one from an Equinox is more difficult) it's just suggested to find a 2000+ and you can run it with any 3100/3400 PCM (but suggest 98-01) For example, my 2005 Equinox engine is being run with a 98 Monte Carlo computer and wiring harness, even though it's from a 3100. I hope I'm making sense, I feel like I'm rambling now...

Thanks so much for the (making it simple info.!) So, hypothetically: If I pulled the 2001 Monte Carlo LA1 engine for my swap, and according to your last paragraph, I use the LA1 stock set-up; all I would have to do is have the PCM reprogrammed to eliminate all the stuff I don't need for my Fiero...right? Can I use the Monte Carlo PCM wire hardess? Just don't want to get into something that I can't handle, or is going to cost a whole bunch more money! The other problem is the dog-bone...right?

Does anyone make a Fiero swap dog-bone kit, or do I have to come up with something of my own? I'm not sure if it was on your Equinox build thread, but I saw where someone used the Rodney Dickmand adjustable dog-bone on the stock brackets! Is it that simple, or does it require a bunch of welding and retrofitting? Can I use my stock '87 motor & transmission mounts, with just the single dog-bone? Or, is that not enough mount for the 3.4 ( I noticed the SUV's have two meaty upper dog-bones!

Yes to use a 2001 Monte Carlo LA1 engine and PCM, you need the PCM to be properly programmed, you will need a 'stock' engine, either a manual Fiero transmission, or the 2001 automatic transmission 4T65E (along with proper length axles) and a wiring harness that will support the LA1 in the Fiero.

And that is most likely the biggest rub. Either you have to make it yourself, or have someone make it for you. No you cant just use the one from the Monte Carlo and somehow rig it up.

quote Originally posted by x-thumpr-x: First off, to make sure everybody is talking about the same motor, refer the motor as it's nomally called, GM made three engine that have a 3.4L displacment. First one would be the F-body (camaro/ firebird) known as 3.4L with iron heads. Second one is the 3.4L DOHC (dual over head cam) found in mid 90's Grand Prix's/ Lumina's. Then you have the 3400 which is a FWD engine. I'm not trying to be rude, but I've seen alot of confusion on the board when members get the motors mixed up. If you want to do a 3400, first thing you should be thinking about is if you want to run OBD1 or OBD2. The stock fiero ECM will not be able to run this motor in a stock set-up. If you want to keep it a simple swap, I'd suggest looking for an F-body 3.4L & put the fiero top end on it. After deciding the 3400's computer choice, decide which method of accessory drives you want on it. I've done three 3400 swaps so far and rebuilt the first one a couple of times with upgrades. My preference is to use the stock 3400 system, but we have built one using the stock Fiero timing cover, water pump & accessories. If you plan on using a manual, an 88 V6 flywheel will be needed. If you go into www.car-part.com & do a search, it will come up with other vehicles that use the same flywheel. GM's 2.2L J-bodies I believe used the same flywheel, that's where I got mine from. Do not use a stock clutch, at first it will hold while you baby the car till it breaks in, after that it's gone in a year. I've done welll with a dual friction centerforce but that's almost gone after 5 years, next will be a Spec stage 2+ or 3 for me. Front engine mount will need minor modding, 84-87 will use a V6 "L" bracket which will need the "hump" grinded off and the motors oil pan will need triming. It is cast and there is an empty cavaity that will be shaved off the corner. With 88s, most of the bracket lines up except for one hole from what I've read (no experience with them) I really suggest you get rodney dickmans poly engine mounts, I've torn apart to sets of new stock rubbers and broken one tranny bracket. I've since gone with Rodneys tranny brackets too. My Alternator sits in the location of the A/C, I don't use the stock alternator, I use a C130 (88 style) which mounts to an A/C compressor bracket from an early 3100 series motor. The upper dog bone section is cut off and minor mods to the bracket for alternator clearance. Once you have this bracket, bring it and an alternatpr to a rebuild shop to size up. A new outer shell will be needed, there are three different sizes with bolt holes 180* apart, the 88 fiero is the smallest size, you need the middle size. Also need a new pulley, mines an 7 groove from a mustang (SC) it's needed to stick out farther then normal to line up with the crank pulley. Power steering pump will be deleted, remove the grooved pulley from the tensioner, a spacer will be needed to install it in the location of the power steering pump. The smooth pulley will then be attached to the tensioner and installed in the lower location normally found on GM 3.1L cavaliers (88-94) new belt will be needed. Make sure you get the exhuast downpipe or at least a foot of it, you will need the flange from it to build you custom exhaust. My upper dogbone is made up from three different brackets welded together. I use the rear section from a V6 dog bone brace, the front section cut off from a 4 cylinder bracket, and the 3400 bracket which bolts the the cylinder head. Takes and afternoon with trial fits to build one, but it hasn't failed on two swaps yet. Coolant lines: if you are 87/88 the heater core return line is in the main under the car, so only one line out is needed and it's located under the throttle body. The return line if needed (pre 87) is the feed line for the throttle body heater. Both lines come back to the trunk wall. Since mines an 87, I deleted the throttle body heater line at the source over the water pump & capped it off with a bleed valve/ refill station. If you plan on using the stock fiero timing cover, a couple of holes need to be plugged on it. you wil run you most of your lines like the 2.8L except for the feed line for the heater core. Throttle cable will need adapting to the new throttle body, this has always been done differently on all my swaps. Some 87/88 4 cylinder cables seem to be able to just fit the bracket, V6's need to be modded. DO NOT use the stock Fiero air canister with the 3400 motor, it will STARVE for air. When I did my first swap, I put a cold air system in and the car dynoed at 175 WHP. Last year the same motor was rebuilt with a regrind cam, ported intake & exhaust, then put into another Fiero which had the stock air canister on it. The car dyno'd 160 WHP same cam was used in a friend 3400 j-body swap and he got 200 WHP out of it. I put the cold air intake on and you could feel the difference. I never got back to the dyno shop though. Now I'm working on a 3500 plenum swap for it. Harness: If you're great with wires and can easily read schematics, shouldn't be hard to build your own. I'm an electrician by trade, my hobby is mechanics so it was a no brainer for me to build. I went OBD1 since a friend of mine did my initial programming for me. We've since started using another forum members tune which is really reliable and no issuses with (Scott999) I believe is his name. There are a couple on the forum that build & sell harness's for the 3400 swap. The harness I prefer to use is a V6 automatic (with A/C if available) Has the most lines in it to work with when rebuilding one for the 3400 swap. 4 cylinder harness doesn't have the same ECM pin connectors as the 7730 ECM so they require a lot more work & soldering. Make sure your get all the connectors for the 3400 motor since they will need to be splced into the harness. For you exhuast, if you can get away without having a cat on your car, you are sooooo lucky. It's the law in Ontario to have one on my car so it's very tight fitting. Mine is probably 3 feet long total, would be 2 feet if i didn't need a cat. Come directly out of the flange and bends right into the cat. Outt of the cat into another flange (for remoaval purposes) then into the stock muffler. I'm running 2.5" cat, which is tight, 2.25" is a better fit. For your gas lines, I would not suggest turning the rail 180*, you would have to pinch the cross over line to get the plenum to fit properly unless you have spacers made to raise the plemun. I routed my gas lines the same way 84-86 4 cylinders have them with the exception of mounting the fuel filter on the lower frame rail. My stock V6 fuel pump worked well with the stock 3400 set-up, I've since upgraded to an 88 corvette fuel pump with the extra work done to the motor. OBD1 ECM used is a 7730 which is found on any gm 3.1L multiport engine, the ecm holder if from any 87/88 fiero with a 4 cylinder engine which has the side plugs on the ECM rather then on the bottom. There's probably more that I can't even think of right now which I've done, I know one day i would like to try an build an OBD2 harness for my own purposes and programming with HP tuners, but not in my udget right now. Here's a link to picture of the swaps I've done. I still need to load up pics from version 2 which uses the stock Fiero front cover. I'll see I can do that now before i go to bed, spent too long writing this out trying to think of what i've done in each swap. http://s913.photobucket.com...ums/ac339/3400Swaps/

I agree wtih the compliments from the other guys about your posting...it is very complete and informative to someone like me, who has very limited knowledge and needs to make decisions on what engine to use for my swap! You have pretty much, if not completely, convinced me to go with the L32, iron head engine from a '93-95 Camaro/Firebird F-body to match my Fiero short block, and Keep all the accessories I've already put into my 2.8 (thinking it was going to last a long time, with only 97k miles when I got it, and now has 119k miles.)

I can use my new Cardone distributor, MSD 48k volt coil, 8mm Magnecore ignition wires, Bosch platinum plugs, 180* stat & 176* fan switch, new Holly adjustable fuel pressure valve, new engine/tranny mounts, Rodney's belt tightener, alternator arm brace, and no EGR or Cat. I also, have a new stage III Spec. clutch, on my Getrag 5-speed, not to mention new Fiero Store adjustable shift cables. I don't want to start all over again from scratch, and I need to keep my expenses down. I want to do everything I can to the L32 swap to get all the performance I can, without losing gas mileage! I get 23-25 around town and 29-32 mpg, on the highway with my 2.8.

I plan on filet welding the exhaust pipes to the header plate, and porting and polishing both the exhaust and intake maniforlds, go to the 17# injectors and maybe a cam kit (what do you suggest?)

[This message has been edited by hypo327 (edited 03-25-2012).]

Okay guys: Based on your advice and expertise I am for sure going to go with the 1993-'95 Camero/Firebird F-body 3.4L Engine! I have found two of them, both in 1995 Firebirds. My first question: (1) Is it beneficial or even practical to use the open square manifold and throttle body? I would think that SFI set-up would give me better fuel delivery!? (2) Also, can I adapt my Fiero dog-bone set-up if I use the Firebird fuel delivery set-up? I would think one would want to use the stock iron heads of the 3.4L engine, do to the superior valve assembly, and bolt the Fiero dog bone bracket to the 3.4 iron head, as it is to the Fiero 2.8 head???
(3) If I can use the stock Firebird manifold & SFI system, is that going to make my Fiero ECM not work properly? If it won't can't I just have it re-programed to work? Here again, I'm just trying to get the most bang (hp) for the buck!!

[This message has been edited by hypo327 (edited 03-28-2012).]

This answer is not going to do your questions justice, but it is a start.

The Fiero ECM can only do batch injection (not Sequential Fuel Injection) and has to be used with a distributor (Not DIS)

The Firebird intake points the wrong way - It will need to be rotated (if it can be)

Will the Firebird intake clear the distributor you will need if you are running the Fiero ECM?

The usual advantage of running a Iron Head 3.4 from a Firebird is that you can use the engine in the stock(ish) Fiero configuration, with the stock(ish) Fiero engine wiring harness and the Fiero ECM.

quote Originally posted by hypo327: (1) Is it beneficial or even practical to use the open square manifold and throttle body? I would think that SFI set-up would give me better fuel delivery!? (2) Also, can I adapt my Fiero dog-bone set-up if I use the Firebird fuel delivery set-up? I would think one would want to use the stock iron heads of the 3.4L engine, do to the superior valve assembly, and bolt the Fiero dog bone bracket to the 3.4 iron head, as it is to the Fiero 2.8 head??? (3) If I can use the stock Firebird manifold & SFI system, is that going to make my Fiero ECM not work properly? If it won't can't I just have it re-programed to work? Here again, I'm just trying to get the most bang (hp) for the buck!!

(1) Beneficial? Not sure on that one. Practical? Not a chance.
(2) The heads are the same between a 3.4 and a 2.8, makes no difference which engine you pull them from.
(3) If you try to adapt the Firebird fuel and intake system, then you are doing the same work you would if you went with the LA1 3400. No, the coolant lines might be easier with the Firebird setup, but the rest is the same...new wiring harness and ECM, new throttle linkage, new fuel lines, new air intake setup.