OK... I am currently trying to sell a 1976 Chevy C-10 Custom Delux to fund my fiero. (Anyone need a truck) With that aside, I have been trying to weigh the pros and cons of the 3.4L and the 3800SC swap. I can get a 3.4L DOHC for $650.00 or a 3800SC for $850.00 I dont know where to go here and would love your input.

I have a 1986 Fiero Coupe that has a 2.5L Iron Duke and a 5 Speed Getrag. I want to go with the best bang for the buck and easiest install. I have never swapped a motor to a non-factory installed motor and I am worried about the wiring and motor mounts etc. However, I have a neighbor and friend in LR that is willing to give me a hand.

My question to you all is... Do I go with the 3.4 DOHC or the 3800SC and how diffucult is the swap and what "extras" would I need with both. I want to make sure I can get everything up front and not let it nickle and dime me to death once I start this project. Right now the car is sitting in the driveway collecting dust and I would love to drive it. When and if I sell my truck I will have the funds to do so. (Trying to get this all planned and absorbe as much of your brain as possible) Thanks for reading and please give me your thoughts.

the DOHC is a older, less reliable motor, that is hard to find in good shape compared to the 3800... No-brainer in my mind that the 3800 is the best choice.

the DOHC might be slightly easier to swap, but a handful of hours takes care of the extra work.

No comparison...3800 hands down....easy install,looks better,easier to work on and the list goes on....If you come to the RRR event in OK next month I will give you a ride in my 3800 Coupe.

quote Originally posted by MstangsBware: No comparison...3800 hands down....easy install,looks better,easier to work on and the list goes on....If you come to the RRR event in OK next month I will give you a ride in my 3800 Coupe.

Doubt I make that. My son will be born the first part of October. Maybe at another event later? :P

OK well tell me this since you have the 3800SC... What all extras do I need? I know I need new engine mounts, what about harness and computer? Also, I am sure I would have to get a new exhaust manifold. What besides that do I need. The 3800SC I am looking at I was told by the seller that I could get the motor, SC, harness, ecm, and fuel pump. Anything else I would need off that Buick before I leave the place? I have seen people comment about purple rain mounts and they are around $400??? So we are already looking at $1,250.00 Would I need a special additional harness and trans mounting brackets? If so, can you point me in the right direction. How much should I plan on spending to perform this swap? Thanks in advance.

Plus "Supercharged" sounds a whole lot tougher than "Double Overhead Cam" when your talking smack

[This message has been edited by phonedawgz (edited 09-21-2010).]

I have a supercharged 3.4L, my friend has a 3400 turbo-charged. Both are Getrag 5-speeds.

We BOTH agree, if we were knew then what we know now, we'd have gone 3800 S/C.

------------------
My World of Wheels Winners (Click on links below)

3.4L Supercharged 87 GT and Super Duty 4 Indy #163

[This message has been edited by fierosound (edited 09-21-2010).]

quote Originally posted by fierosound: I have a supercharged 3.4L, my friend has a 3400 turbo-charged. Both are Getrag 5-speeds. We BOTH agree, if we were knew then what we know now, we'd have gone 3800 S/C.

He was asking about the 3.4l DOHC vs. the 3800.

But since you mentioned it, what are your reasons for wishing you had done a 3800 SC versus a supercharged or turbo 3.4L ?

quote Originally posted by pdemondo: He was asking about the 3.4l DOHC vs. the 3800. But since you mentioned it, what are your reasons for wishing you had done a 3800 SC versus a supercharged or turbo 3.4L ?

Really that would be a good reason to help sway my decision. Lol.

Naturally I want the HP that the 3800 produces. However I am worried about the install pertaining to the mounting brackets (both engine and trans) and te wiring.

quote Originally posted by GADJet: Really that would be a good reason to help sway my decision. Lol. Naturally I want the HP that the 3800 produces. However I am worried about the install pertaining to the mounting brackets (both engine and trans) and te wiring.

I am working on a 3.4L DOHC now. Mounts, of course, are not a problem. I am using the Rodney D. poly trans mounts and motor mount. I used the stock 88 GT clutch and
flywheel. My harness is being done by forum member Erik, should have that back in a week or so.

I don't think any of these are a problem with the 3800 SC either. There are a few forum members who sell custom engine and trans brackets for the 3800, as well as, will build a harness for you.

So you may save some moeny on not needing custom mounts with the DOHC. In the long run, however, a few hundred extra spent up front, isn't that much of a difference.

I have been going back and forth (still am) and I have driven a 3.4 DOHC and a 3.8 s/c. If you search you'll probably see a few of my threads about this question.

It won't help, but its good advice. It depends on what kind of car you want. L67 if you like going fast in a straight line, or DOHC if you want a "ferrari" zipping around corners etc.

DOHC = high revving spirited driver, owning the turns and a sweet power band that goes from 3500 to... well the rev limiter which can be 7k+ and its cheaper. Usually less dependable, probably due to the high revving to get the power. Properly done, I would think I nice DOHC would be pretty dependable.
L67 = fast as heck, tons of bottom end, and dependable, but more expensive and I believe takes more work to swap in.

I'm (probably) going L67 personally, but I plan it for a daily driver. If I ever get the time/money I'm so turbo'ing (is that an actual term?) a 3.4l DOHC

DOHC: cheap/high revs/nice powerband/easy install
L67: expensive/fast out of the box/dependable

There is a member that said something that has stuck with me.
You car can be:
1.) Fast
2.) Cheap
3.) Dependable
Pick 2

~Any feel free to correct me if I'm wrong about something~

quote Originally posted by GADJet: Doubt I make that. My son will be born the first part of October. Maybe at another event later? :P OK well tell me this since you have the 3800SC... What all extras do I need? I know I need new engine mounts, what about harness and computer? Also, I am sure I would have to get a new exhaust manifold. What besides that do I need. The 3800SC I am looking at I was told by the seller that I could get the motor, SC, harness, ecm, and fuel pump. Anything else I would need off that Buick before I leave the place? I have seen people comment about purple rain mounts and they are around $400??? So we are already looking at $1,250.00 Would I need a special additional harness and trans mounting brackets? If so, can you point me in the right direction. How much should I plan on spending to perform this swap? Thanks in advance.

Motor/trans
Mounts
Harness
PCM
Axles
Fuel Pump
Hoses
Gaskets
Exhaust parts
Muffler
Shift bracket/Lever
Time/tools

My suggestion is that you talk directly with the guys that have the 3.4 DOHC swap. Most of them seem to love their engines and they can fill you in on why they chose to go that route.

This thread, if you haven't already see it, has lots of links discussing the pros and cons of the 3.4 DOHC along with lots of information: https://www.fiero.nl/forum/Forum1/HTML/062728.html

Generally these topics become a bit of a slug fest over who's choice of engine is the best and and why all the others are crap. So there may be some bumps ahead.

Nolan

The two engines are not really good to compare to each other. They are completely different animals. One is a naturally aspirated high reving engine. The other is a forced induction high torque and with mods, high horse power engine. IMO the only fair comparison to the 3800SC is a SBC but that is a different subject.

If you want to go for high horsepower, then get the 3800SC. If you want something more exotic, then get the 3.4 DOHC.


Generally, people that install the 3800SC also use the auto tranny that goes with it. People who install the 3.4 DOHC use the manual trannies on the Fiero. One combination turns the car effectively into a high horsepower muscle car. The other combination turns it into more of an exotic performance car.

It is all about personal preference.

quote Originally posted by Doug85GT: The two engines are not really good to compare to each other. They are completely different animals. One is a naturally aspirated high reving engine. The other is a forced induction high torque and with mods, high horse power engine. IMO the only fair comparison to the 3800SC is a SBC but that is a different subject. If you want to go for high horsepower, then get the 3800SC. If you want something more exotic, then get the 3.4 DOHC. Generally, people that install the 3800SC also use the auto tranny that goes with it. People who install the 3.4 DOHC use the manual trannies on the Fiero. One combination turns the car effectively into a high horsepower muscle car. The other combination turns it into more of an exotic performance car. It is all about personal preference.

Well, I have the 5 Speed and am not likely to change that to an auto. I do want power but still want economy as well. It will be a weekend warrior/semi daily driver. Heck, I may go all out daily driver. But with a stock 3800 SC it should be fine. I dont have to have a ton of HP but the 240ish that that motor generates will be sufficient. I have really had my eye on the 3800 every since I started looking at engine swaps. Well that and an LS6. But I can not afford an LS6 or the mandatory labor or extras that go with it so I am fine with the 3800.

I dont plan on doing aything to the getrag unless you pros give me better insite as to a good reason I should. The clutch was replaced 8000 miles ago (by the previous owner) and should be fine.

quote Originally posted by GADJet: Well, I have the 5 Speed and am not likely to change that to an auto. I do want power but still want economy as well. It will be a weekend warrior/semi daily driver. Heck, I may go all out daily driver. But with a stock 3800 SC it should be fine. I dont have to have a ton of HP but the 240ish that that motor generates will be sufficient. I have really had my eye on the 3800 every since I started looking at engine swaps. Well that and an LS6. But I can not afford an LS6 or the mandatory labor or extras that go with it so I am fine with the 3800. I dont plan on doing aything to the getrag unless you pros give me better insite as to a good reason I should. The clutch was replaced 8000 miles ago (by the previous owner) and should be fine.

You will need a new clutch that will handle the 3800 motor or you will not be able to use the swap to it's full potentional. If staying 5 speed then you will need modded flywheel, new clutch, mounts, ect......

I'll weigh in on the 3.4 DOHC side. I have a 96 3.4 DOHC in my 85 SE with a 5 speed Getrag. The change in the car from the 2.8 to the 3.4 is to me Day and Night, the 3.4 with the Getrag is what GM was going for (90 Prototype) before the Fiero was killed. My 3.4 can do the speed limit in town in first gear and once it hit 3500 rpm it puts yuo back in the seat as it just screams up to the 7k red line. It is a fun car to drive and is also very docile driving around town. I put my car on the Dyno and we got 205 Hp and 201 Ft Lbs of torque to the ground, which doesn't put it that far behind a 3800SC. Now throw 8 pounds of boost to the engine and your talking 350 HP.
My other Fiero has a 4.9 in it and I love both cars the 4.9 is all torque and fast shifts ( 5k and she out of go) so depending on how I feel is the V8 rumble or the 3.4 screamer.



Dyno from my 3.4 DOHC

As others have stated it all in what you want from your car.

Joe Sokol

------------------
85 SE Daily driver with a 3.4 DOHC OBD II
88 Formula/GT 4.9 Allante Intake (My Baby)

quote Originally posted by MstangsBware: You will need a new clutch that will handle the 3800 motor or you will not be able to use the swap to it's full potentional. If staying 5 speed then you will need modded flywheel, new clutch, mounts, ect......

Can you give me more info on this? I want to make sure I do get the correct parts.

quote Originally posted by Fieroking: I'll weigh in on the 3.4 DOHC side. I have a 96 3.4 DOHC in my 85 SE with a 5 speed Getrag. The change in the car from the 2.8 to the 3.4 is to me Day and Night, the 3.4 with the Getrag is what GM was going for (90 Prototype) before the Fiero was killed. My 3.4 can do the speed limit in town in first gear and once it hit 3500 rpm it puts yuo back in the seat as it just screams up to the 7k red line. It is a fun car to drive and is also very docile driving around town. I put my car on the Dyno and we got 205 Hp and 201 Ft Lbs of torque to the ground, which doesn't put it that far behind a 3800SC. Now throw 8 pounds of boost to the engine and your talking 350 HP. My other Fiero has a 4.9 in it and I love both cars the 4.9 is all torque and fast shifts ( 5k and she out of go) so depending on how I feel is the V8 rumble or the 3.4 screamer. As others have stated it all in what you want from your car. Joe Sokol

That sounds good Joe but I dont want to have to add extra to it to get to that point. As speaking of the boost your referring to. Adding a turbo or SC as an add on will cost me out the butt. I can get the entire 3800 with SC for $850.00

quote Originally posted by GADJet: That sounds good Joe but I dont want to have to add extra to it to get to that point. As speaking of the boost your referring to. Adding a turbo or SC as an add on will cost me out the butt. I can get the entire 3800 with SC for $850.00

I hope you don't think the 3800SC makes 350 hp stock.

In stock form here are the two engines:

3.4 DOHC
--210 hp
--215 ft/lb

3800SC
--240 hp
--270 ft/lb


There are some relatively cheap upgrades that you can do to get more power out of the 3800SC but it doesn't come that way. Also, you can regrind the cams on the 3.4 DOHC and get another 50-60 hp out of it. Both engines benefit from a better exhaust. The 3.4 DOHC also benefits from fabbing a better intake.

One big difference is that there are off the shelf upgrades that you can buy for the 3800SC while almost everything you can do with the 3.4 DOHC would have to be custom fabbed.

Speaking of custom DOHC cams, does anyone have the specifications for them? The extra 50 hp sounds interesting

quote Originally posted by Doug85GT: I hope you don't think the 3800SC makes 350 hp stock. In stock form here are the two engines: 3.4 DOHC --210 hp --215 ft/lb 3800SC --240 hp --270 ft/lb There are some relatively cheap upgrades that you can do to get more power out of the 3800SC but it doesn't come that way. Also, you can regrind the cams on the 3.4 DOHC and get another 50-60 hp out of it. Both engines benefit from a better exhaust. The 3.4 DOHC also benefits from fabbing a better intake. One big difference is that there are off the shelf upgrades that you can buy for the 3800SC while almost everything you can do with the 3.4 DOHC would have to be custom fabbed.

No, I know that it doesnt make 350 from the factory. I have been reading wikipedia! LOL. I don't care much for doing anything "EXTRA" to the motor other than pulling it from one car and then putting it into mine. (Unless it needs to be re-ringed or something) That aside, wikipedia says 240 on the 3800SC and about 160 on the 3.4 DOHC. I also know that wikipedia is edited by joe blow and anyone can put anything on it. However, your talking about a 80 HP difference from the factory without making any changes. (provided that info is correct)

My fears are the tranny and wiring and mounting brackets for the tranny and motor.

quote Originally posted by GADJet: No, I know that it doesnt make 350 from the factory. I have been reading wikipedia! LOL. I don't care much for doing anything "EXTRA" to the motor other than pulling it from one car and then putting it into mine. (Unless it needs to be re-ringed or something) That aside, wikipedia says 240 on the 3800SC and about 160 on the 3.4 DOHC. I also know that wikipedia is edited by joe blow and anyone can put anything on it. However, your talking about a 80 HP difference from the factory without making any changes. (provided that info is correct) My fears are the tranny and wiring and mounting brackets for the tranny and motor.

You are looking at the wrong listing for the 3.4. 160 hp is the 3.4 pushrod engine. The 3.4 DOHC is 210. If it does not say "LQ1" then you are looking at the wrong listing.

quote Originally posted by Sourmug: Speaking of custom DOHC cams, does anyone have the specifications for them? The extra 50 hp sounds interesting

You actually posted in the thread with them:

https://www.fiero.nl/forum/A...-1-064798-3.html#p88


Stock 3.4 DOHC dyno 175-185. Those cam specs dynoed 230 hp. A pickup of about 50 hp.

quote Originally posted by Doug85GT: In stock form here are the two engines: 3.4 DOHC --210 hp --215 ft/lb 3800SC --240 hp --270 ft/lb

Not quite correct.

The LQ1 3.4 DOHC was rated at 200 - 215 HP and 215-220 TQ depending on year and whether or not it came with an auto or manual trans.

The 3800 Series 2 SC engine was rated at 240hp and 280tq. The 3800 Series 3 SC engine was rated at 260hp and 280tq.

A stock 3.4 DOHC V6 swap in a Fiero using a getrag 5-speed can net you low 14's to high 13's in the 1/4 mile.

A stock 3800 Series 2 SC swap in a Fiero (with good exhaust and induction) using an auto trans usually gets mid to low 13's in the 1/4 mile. Slightly faster if you have a manual trans.

-ryan

------------------
7+ years on this same swap -- NO engine or transmission failures...

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

quote Originally posted by Doug85GT: You actually posted in the thread with them: https://www.fiero.nl/forum/A...-1-064798-3.html#p88 Stock 3.4 DOHC dyno 175-185. Those cam specs dynoed 230 hp. A pickup of about 50 hp.

LOL, OK that's funny. Thanks

quote Originally posted by Doug85GT: You are looking at the wrong listing for the 3.4. 160 hp is the 3.4 pushrod engine. The 3.4 DOHC is 210. If it does not say "LQ1" then you are looking at the wrong listing.

Thanks Doug.

quote Originally posted by Darth Fiero: Not quite correct. The LQ1 3.4 DOHC was rated at 200 - 215 HP and 215-220 TQ depending on year and whether or not it came with an auto or manual trans. The 3800 Series 2 SC engine was rated at 240hp and 280tq. The 3800 Series 3 SC engine was rated at 260hp and 280tq. A stock 3.4 DOHC V6 swap in a Fiero using a getrag 5-speed can net you low 14's to high 13's in the 1/4 mile. A stock 3800 Series 2 SC swap in a Fiero (with good exhaust and induction) using an auto trans usually gets mid to low 13's in the 1/4 mile. Slightly faster if you have a manual trans. -ryan

OK well with that being said.... I can deal with 200 HP. That is much closer to where I want to be. I definately want to be above 200HP. I knew the 3800SC would easily obtain that. Well if the 3.4L will get me to 200HP would I still need to change the clutch and axles as well?

quote Originally posted by GADJet: OK well with that being said.... I can deal with 200 HP. That is much closer to where I want to be. I definately want to be above 200HP. I knew the 3800SC would easily obtain that. Well if the 3.4L will get me to 200HP would I still need to change the clutch and axles as well?

The DOHC does not need any modification to the axles. It bolts right up to the engine. Some people have used the stock clutch. I would recommend a stronger clutch with that engine.

quote Originally posted by GADJet: Can anyone give me a ball park on the cost of this? This is what I am estimating so far. Motor $850.00 Trans-F40 $700.00 or $300.00 to ues the Getrag and get new clutch kit. Mounts $500.00 Harness $500.00 PCM ? Axles ? Fuel Pump Comes with motor Hoses ? Gaskets ? What gaskets? I am not cracking the motor open. Exhaust parts ? Muffler $150.00 Shift bracket/Lever ?

Motor $850.00---You can find a better deal then this....just keep looking and have the cash ready...
Trans-F40 $700.00 or $300.00 to ues the Getrag and get new clutch kit.---Use the Getrag you have with SPEC clutch and call it a day(F40 is nothing special)
Mounts $500.00---Mounts will only run you about $200 or so
Harness $500.00---Can get it done for $400 if you have the stock 3800 harness
PCM $40 plus $100 to have it programmed
Axles $0 if you use the Getrag
Fuel Pump $100 being you will need a new one
Hoses $30 bucks if you buy new ones
Gaskets $75 I am not cracking the motor open.(I like to replace the gaskets from the LIM up being they have been revised several times)
Exhaust parts $50 bucks for all mandrel bends needed
Muffler $150.00(can find a used Flow Master from Camaro for $40 off CL
Shift bracket/Lever $0(can be made if you have a hacksaw/welder
ADDED:Modded 3800 Flywheel $100 and up(can find them on here from time to time)

I've installed both engines. The 3800 fits better, and I thought it was an easier swap. Maybe I was doing it wrong...?

Edit: By the way look at how big the DOHC is compared to the 3800. People say the DOHC has a "take curves fast" characteristic. When I drove one, I thought more along the lines of "holy sh*t the tail wants to come out".

[This message has been edited by L67 (edited 09-23-2010).]

quote Originally posted by L67: I've installed both engines. The 3800 fits better, and I thought it was an easier swap. Maybe I was doing it wrong...? Edit: By the way look at how big the DOHC is compared to the 3800. People say the DOHC has a "take curves fast" characteristic. When I drove one, I thought more along the lines of "holy sh*t the tail wants to come out".

Man that 3.4 looks like a 5.7. Lol

You sure your not lying to me about that. Lol. Jk.
Man, what to do, what to do!!!

Try and get a ride (or drive) in one of each, if possible.
They're both great engines but they have very different personalities. The 3800SC is more of a brute - like a mini-small block Chevy. The 3.4 DOHC is more of a high-rev engine that has a more exotic personality. Like the difference between a Corvette and a Ferrari.

Both have been done enough that you can get any info, mounts, ect. needed pretty easy. If you're going to leave them both stock, you're looking at about a 30 HP difference. Certainly the 3800SC would be faster, but unless you time it at the track, the difference won't mean much on the street. I have a 2000 Trans Am as well as my 88 Fiero, and even though the stock 2.8 has less than half the power of the TA's LS1, I still really enjoy driving it because of the way it feels and drives.

My personal preference would be a 3800SC if I went with an automatic or a 3.4 DOHC with a 5-speed.

Just an opinion from what all I have read....

The 3800 seems to be a better built engine by design and therefore more dependable. It also made Engine of the year a few times if I recall correctly and are plentyful.
When looking for one for mine (have not got it in yet) I had found on carparts.com yards listing '07 NA 3800s from a Lucerne for under $500 for the long block with only 5000 miles
on it. You will need a better clutch and that engine along with alot of these others WILL trash most trannys if you keep going crazy on it like side stepping the clutch, otherwise it
should be good for a long while.


All engine swaps have there pros and cons but for dependability its hard to beat the 3800 SC or NA and both will put you over the 200 HP mark with tons of aftermarket parts to
raise the HP more if you ever wish to.

Steve

[This message has been edited by JumpStart (edited 09-23-2010).]

quote Originally posted by JumpStart: Just an opinion from what all I have read.... The 3800 seems to be a better built engine by design and therefore more dependable. It also made Engine of the year a few times if I recall correctly and are plentyful. When looking for one for mine (have not got it in yet) I had found on carparts.com yards listing '07 NA 3800s from a Lumina for under $500 for the long block with only 5000 miles on it. You will need a better clutch and that engine along with alot of these others WILL trash most trannys if you keep going crazy on it like side stepping the clutch, otherwise it should be good for a long while. All engine swaps have there pros and cons but for dependability its hard to beat the 3800 SC or NA and both will put you over the 200 HP mark with tons of aftermarket parts to raise the HP more if you ever wish to. Steve

a '07 Lumina? The mid 90's Lumina's had 3800's but they were replaced by the Malibu, which only had the 3.1 and later the 3.5/3.9.

The 3.4 TDC has a reputation to be expensive to maintain, how founded that is, I don't know -- I do know it has a timing chain and 2 timing belts that is labor intensive to replace. The 3800 is a well proven workhorse that outlasts most other motors from any manufacturer. That being said, I would personally prefer a high-revving motor in a car like a Fiero if I had the choice (and I would definitely prefer a manual transmission).

quote Originally posted by masospaghetti: a '07 Lumina? The mid 90's Lumina's had 3800's but they were replaced by the Malibu, which only had the 3.1 and later the 3.5/3.9.

My bad.... I corrected it. It was an '07 Buick Lucerne

Steve

quote Originally posted by masospaghetti: The 3.4 TDC has a reputation to be expensive to maintain, how founded that is, I don't know -- I do know it has a timing chain and 2 timing belts that is labor intensive to replace. The 3800 is a well proven workhorse that outlasts most other motors from any manufacturer. That being said, I would personally prefer a high-revving motor in a car like a Fiero if I had the choice (and I would definitely prefer a manual transmission).

1 timing chain and 1 timing belt. It is a bit odd to have both but that is what GM did.

As far as more expensive to maintain, you have to replace the timing belt. That is standard on most DOHC engines. I know that is something new for Fiero owners but it is pretty standard on the vast majority of cars on the road right now. If anyone does not want to deal with timing belts, then stick to pushrod engines. There is nothing magical or complex about a timing belt. They just require replacement every 60,000 miles.

If you compare the 3.4 pushrod to the 3.4 DOHC, you get 50 more horsepower. I think that is a fair price to pay for those extra horses and is cheap IMO. CI per CI, a DOHC engine will make more hp than a pushrod engine. Forced induction is a different matter but with similar setups, a FI DOHC engine will still produce more hp than a FI pushrod.

quote Originally posted by Doug85GT: 1 timing chain and 1 timing belt. It is a bit odd to have both but that is what GM did. As far as more expensive to maintain, you have to replace the timing belt. That is standard on most DOHC engines. I know that is something new for Fiero owners but it is pretty standard on the vast majority of cars on the road right now. If anyone does not want to deal with timing belts, then stick to pushrod engines. There is nothing magical or complex about a timing belt. They just require replacement every 60,000 miles.

I'll attest to that. My brother had a 92 Lumina Euro that had one of those service crate 3.4 DOHC engines installed in it. He put about 68,000 miles on that service crate engine and never replaced the timing belt. Well, it failed on him while he was doing 70mph on the interstate. All of the info we could find online about the 3.4 DOHC engine said the 91-95 motors were supposed to be non-interference engines (ie: if the timing belt fails, the valves should not hit the pistons). So my brother replaced the timing belt and ended up finding out some valves did indeed kiss the pistons and bent when the belt let go.

-ryan

If I were doing the swap I would go with the 3800. In any form they are just about bulletproof. Think about how you would change the timing belts on the DOHC; they would eventually need service.

I would go 3800 or aluminum head 60degree but for what it's worth I did a timing belt in the car on a 3.4TDC. It was pretty easy actually. just had to remove the rear 2 cradle bolts to swing the engine down. The only issue I have with the 3.4tdc is that they are old and hard to come by in good condition.

quote Originally posted by GADJet: Man that 3.4 looks like a 5.7. Lol You sure your not lying to me about that. Lol. Jk. Man, what to do, what to do!!!

Yeah, the 3.4TDC is heavy... about 70 lb heavier than its pushrod counterparts. And most of that extra weight is in the top half of the engine (the extra cams and bigger heads).

If it were me, I'd go for the 3500 V6 (RPO code LX9). It has a pushrod valvetrain and aluminum heads, which makes it about 70-80 lb lighter than the 3.4TDC. And the performance is pretty close. The end result is a higher power-to-weight ratio, and a lower center of gravity.

quote Originally posted by L67: I've installed both engines. The 3800 fits better, and I thought it was an easier swap. Maybe I was doing it wrong...? Edit: By the way look at how big the DOHC is compared to the 3800. People say the DOHC has a "take curves fast" characteristic. When I drove one, I thought more along the lines of "holy sh*t the tail wants to come out".

The 3800 and the 3.4 DOHC are very similar in weight. I noticed no difference in how my car handled from a 2.8 to the 3.4dohc swap. It handles around corners very nice but due to more power you can hang the tail out if your not careful