Short version: ACES EFI is the best option for a quick build with minimal wiring and great performance – it’s affordable and is even boost ready. I installed it in a weekend.
Now more info;
I’ve converted a Cadillac 4.9 swap to use the Aces EFI Deuces Wild kit, and have to say it is one the best options I’ve found. I’ve been on Pennock’s for almost 20 years and find it to be a great community that has helped quite a bit with my projects – so I figured I’d document the Aces setup to help others. My first car was/is an 81 X-11 Citation that I did my first 4.9 swap in circa 2004. At the time there was only a homemade software available and it basically just turned off VATs and adjusted timing, so modifying the 4.9 and keeping MPFI was not a thing. I asked TunerCats about 20 times to support the Caddy motors and they eventually came through but it still meant the swap was a wiring challenge and did not come out until after I did custom engine work. For me, one of the biggest annoyances running a Caddy ECM is the inability to tell it the AC is on so it will correct idle. At the time I figured out an LT1 PCM was my best bet for available tuning support, and would give me tuning with a knock sensor so I didn’t destroy the engine. I made a custom distributor and ended up rewiring my X-11 3 times until I got it dialed in enough = a lot of time and effort.
Fast forward to 2023, I swapped a 4.5 into an 81 Buick Skylark to be my daily driver/ budget beater. I did it as an exercise in a cheap build and knew the setup would not be ideal, but I was still way off- it sucked !! The Caddy TBI setup has zero support for making any adjustments so the higher stock idle and lack of AC compressor offset were major irritants, so I looked to replace with a 4.9 and possibly use a truck TBI ECM. Then New Years 2025, a good buddy (Master Yoda) sent me a link to the Aces EFI sale. I read up on it and it is everything I would ask for in a kit – Self tuning, wideband O2 for accuracy, AC input for idle correction, fan controls, handheld programmer/ display and a programmable output that I hope to use to lock up the Torque converter (currently using a vacuum switch) and comes with a 3 bar map so it is boost ready. It was a little more money than a truck TBI harness and ECM, plus figuring out the tuning. I considered it would be considerable less time to get running and the additional features made the Aces setup worth it and pulled trigger. I actually bought two, the other is for a turbo 3.1 build down the road.
I rebuilt a Caddy 4.9 to replace the 4.5 with a 4T60/ 440T4 trans. Aces offers a trans controller if you want to use the 4T60”E” that comes with the 4.9. I had previously rebuilt the 4T60 and it only has a few thousand miles, so there was no need to replace it. I may use their trans controller on a future swap with their Wild Card kit for Sequential EFI to run multiport injection with the Allante intake setup.
The most important thing for this swap that is not part of the kit is the distributor – Cadillac 4.X do not have aftermarket options for distributors, but thankfully the answer is on the forum. A few members here figured out converting the Caddy distributors to vacuum advance in order to run carburetors, which is great but their threads lost the pics years ago because they were links to Photobucket, etc. I did a post on how to do this and uploaded photos as attachments in the hope they stay searchable for others.
The second required item is fuel pump/ pressure control. The Aces unit is programmable for 43.5 – 58 psi fuel pressure, but they recommend 58 psi. Evil energy sells 58 psi braided line kits with corvette style 58 psi filter/regulator for under $100 so that was no brainer. I got a fuel pump for a 98 LS1 Camaro/Corvette that is good for the 58 psi. The only other significant thing I had to get was a 2300 carb to GM TBI adapter – they are plentiful on eBay, I opted for a composite one to prevent heat transfer to the TBI unit and it was cheaper.
The next thing was the throttle and trans TV cables - adapter setups are available from several sources, but I like repurposing where I can so I modified the stock 4.5 cable bracket. The 4.5 cable bracket is spaced side by side which is close to how the Aces TBI throttle plate arm is configured. The 4.9 bracket has cables stacked on top on each other which would require more modification. I'm not sure how that would work with a Fiero throttle cable.
The last two items were EGR and air cleaner. I just deleted the EGR and used a piece of flat steel with a gasket. I reused the stock Caddy 4.5 air intake and filter box.
The parts lists:
620 Deuces Wild kit + shipping (Sale)
50 98 Camaro fuel pump - rock auto
85 EVIL ENERGY 6AN Fuel Line Kit, with LS Swap Fuel Filter Regulator 58PSI 6AN CPE Hose Braided Fuel Line Fitting Kit 20FT
25 Throttle body adapter - eBay Intake Manifold Adapter For Chevy TBI Throttle For Holley 4412 2300
Very cool! I was able to get my 4.9 / Allante / 5 speed setup running decently on the 2240 PCM, really by modifying only 2-3 parameters. The rest was just minor tweaking for driveability and personal preferences. (DFCO, idle speed, etc.) As you mentioned, the ability to correct for idle when the A/C kicks in is the last remaining "gotcha". It hunts badly when it's hot, and you get off the highway and stop, with the A/C running.
Of course, wideband O2, among other things, would be cool. Thanks for sharing.
Very nice work. Now you just opened the door for a more aggressive CAM from Delta camshafts if you so desire. The lack of fueling support is the biggest limitation for the stock injected 4.9, amongst other things.
Very cool! I was able to get my 4.9 / Allante / 5 speed setup running decently on the 2240 PCM, really by modifying only 2-3 parameters. The rest was just minor tweaking for driveability and personal preferences. (DFCO, idle speed, etc.) As you mentioned, the ability to correct for idle when the A/C kicks in is the last remaining "gotcha". It hunts badly when it's hot, and you get off the highway and stop, with the A/C running.
Of course, wideband O2, among other things, would be cool. Thanks for sharing.
Happy to help - got plenty from folks on here over the years. The AC offset is seamless now, I'm really happy with it. I got their CDI ignition to install this weekend to gain timing control, so will post once I have it working.
I'm gonna be hitting up their techs to figure out a hall effect ignition option/setup - it's the only unsolved item for using a Wild Card or Joker sequential EFI unit on an Allante intake motor....
Very nice work. Now you just opened the door for a more aggressive CAM from Delta camshafts if you so desire. The lack of fueling support is the biggest limitation for the stock injected 4.9, amongst other things.
Thanks, and that was the plan - I did the LT1 PCM setup to run the .500" lift Delta Cam in my X-II which was a lot of work to say the least! Now there is a bolt on option for cams and/or turbos.
Nice work but why do you need a vacuum advance distributor when you are using a Aces ECM? The Aces unit is supposed to be self tuning right?. Just for reference on my 4.9L I used the stock 2240 ECM and the engine starts and runs good with a couple of degrees timing advance and 93 octane premium gasoline.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Nice work but why do you need a vacuum advance distributor when you are using a Aces ECM? The Aces unit is supposed to be self tuning right?. Just for reference on my 4.9L I used the stock 2240 ECM and the engine starts and runs good with a couple of degrees timing advance and 93 octane premium gasoline.
Hey man, I was just about to post an update and review.
Short answer – no, you don’t need the vacuum advance distributor. When I started I didn’t know exactly how it would work given I couldn’t find anyone else that tried this swap, plus the instructions recommend starting without the Aces unit controlling timing. Now that I have it running great, I would tell whoever does an Aces swap to use the stock distributor with remote coil conversion – I’ll give details in the update.
Following the wiring install I ran the setup wizard and it started first time (after allowing fuel pump to prime). After it warmed up, the TPS/throttle plate needed some adjustment on the set screw and then the TPS relearn wizard to get desired idle – which was straight forward. First drive ran good, like surprisingly good for having only done a few inputs in the start up wizard.
After a few drives for it to learn it started hunting idle when at operating temperature. Initial message to Tech support and they told me the obvious – check for vacuum leak. I knew there wasn’t one because I just built the motor, so I did a dive into YouTube videos of other Aces builds and found a Camaro guy running a KillShot unit (4 barrel version) that showed how to use the Aces tuning software to adjust fueling. The Aces software is pretty easy to use once I understood how it is setup. I found it was at the limit of pulling fuel @ 30%. There is a single parameter to adjust the entire fuel map that correlates to the start up wizard of stock, mild or race options (Stock Fuel Table Offset). It was at 90% out of the box, but consider it’s mainly geared at traditional small block motors so the 4.9 would need less fuel. I set the offset to 75%, changed target Air/Fuel ratios to 14.7 at idle and 14.9 at lean cruise and it cleaned up the idle and drives better.
Now that I had fuel adjusted, it was time for the ignition upgrade. I’ll put details in the next post, so short version is I went back to the stock distributor without the ignition module and harness, using only the magnetic pick up and setting timing to 15*. I looked up the stock timing table for a 4.9 and input the table into the tune so the Aces ECM could control timing – now it runs great !!
I don’t normally do product reviews, but I am really happy with the Aces equipment – it ran good out of the box and runs great with just a little tweaking. One of the things I like about Aces is their software is free, you can download it and check it out without buying anything. I’ll post my current calibration file so anyone can load it on a similar setup and it should run great, or just to check it out - https://acesefi.com/pages/software There are some complaints and truth that it can be hard to get ahold of Aces support, but realize they are a small company that is growing fast. When I have spoken to their staff, they have been helpful. I would recommend Aces to anyone that wants a cleaner, faster swap and to those that might be a little less savy with wiring and tuning.
Let me know if you have any questions I can help with.
Cheers
Edit - well, the file won't attach - message me if you want it.
[This message has been edited by 81 4.9L X-11 (edited 05-24-2025).]
After getting the Deuces Wild installed and running, I could tell more timing control would get it to run better. I decided to get the Aces High Roller kit – which is a CDI box, coil and wiring harness for just $140 (I bought 2 so shipping was free). Looking at the specs, it fires the plugs more times per revolution with more energy than MSD and other CDI boxes, so I figured it was worth a shot. Just to state it – you do not need the CDI, the Aces ECM will run the motor with just an Aces remote coil ($50), the connector is part of the harness the ECM comes with. Either option requires a conversion from the in-cap coil to a remote one. FAST sells a kit, which is just a brass post and made to fit plug wire $57. I will be looking for another option but this got it done fast…
FAST GM HEI Coil In Cap Conversion Kits 730-0590
[EDIT - don't buy this the brass button for the cap was a pile of shavings in less than 1,000 miles. I'm working on a stainless option and will post when done.
I looked at the crowed engine bay and decided it was time for some arts and crafts, so grabbed some steel to make a strut tower brace that I could mount the CDI box and remote coil to. The bar I used was the center of the strut brace from the donor Cadillac Deville.
I will be fine tuning the next couple of weeks, and I’ll share the calibration file when I think it done or as good as I can get without being a tuner. Hope these posts helps someone…
[This message has been edited by 81 4.9L X-11 (edited 07-04-2025).]
Hey there. I have an 84 skylark and this post convinced me to do the 4.9.
What did you use for mounts? I have a 4 speed so I think my only worry will be shifter cables... maybe.
I used West Coast Fiero mounts for the transmission in all my swaps - stock rubber ones will fail quickly. This is my 3rd iteration of 4.9 swap and I've done the motor mounts different each time. The best in my opinion is to fabricate front and rear motor mount brackets to use energy suspension RWD trans mounts - you end up poly mounts in all 4 corners and don't need a dog bone. The rear motor mount is the most challenging. In two of my swaps I turned the L bracket from the stock V6 mount under the crank and used stock mount there. The front motor mount is the easiest to make if you have a welder - I attached a couple pics. This one I used gussets, the previous was boxed out - they both great with the stock Caddy bracket. If you are going to fab a rear motor mount, grab one off a 90-93 El Dorado. Well, that is if you use the 4t60 trans. You said you have a 4 speed, unless you luv manuals I definitely recommend the auto - with stock gears it purrs on the highway.
Good luck with the swap, let me know if you have any more questions.
[This message has been edited by 81 4.9L X-11 (edited 07-04-2025).]
Don't buy the FAST GM HEI Coil In Cap Conversion Kits 730-0590 - the brass button for the cap was a pile of shavings in less than 1,000 miles. I'm working on a stainless option and will post when done.
I used West Coast Fiero mounts for the transmission in all my swaps - stock rubber ones will fail quickly. This is my 3rd iteration of 4.9 swap and I've done the motor mounts different each time. The best in my opinion is to fabricate front and rear motor mount brackets to use energy suspension RWD trans mounts - you end up poly mounts in all 4 corners and don't need a dog bone. The rear motor mount is the most challenging. In two of my swaps I turned the L bracket from the stock V6 mount under the crank and used stock mount there. The front motor mount is the easiest to make if you have a welder - I attached a couple pics. This one I used gussets, the previous was boxed out - they both great with the stock Caddy bracket. If you are going to fab a rear motor mount, grab one off a 90-93 El Dorado. Well, that is if you use the 4t60 trans. You said you have a 4 speed, unless you luv manuals I definitely recommend the auto - with stock gears it purrs on the highway.
Good luck with the swap, let me know if you have any more questions.
Thanks. I'm sure I'll pick your brain as I go along.. I have a partially complete takeout from a 93 Eldorado with 60K miles. Looks like I need different exhaust manifolds because mine both dump down the 'sides' of the engine. I need a conventional crossover setup like every other GM FWD.
I have injector holes I need to do something too, that it looks like you don't have?
I have a 4spd from an 81 Skylark which should be numerically lower than a Fiero (or an X11). Should be around 2500 @ 75 MPH or so.
One tough part about living in Massachusetts, all this stuff is long gone.
It runs great and revs out without issue, I haven't truly beat on it yet but can tell it wants more timing on the top end. I'm working on a low buck knock sensor setup to toggle spark retard via the NOS input on the Aces unit - will give me more confidence to chase the higher end performance.
Thanks. I'm sure I'll pick your brain as I go along.. I have a partially complete takeout from a 93 Eldorado with 60K miles. Looks like I need different exhaust manifolds because mine both dump down the 'sides' of the engine. I need a conventional crossover setup like every other GM FWD.
I have injector holes I need to do something too, that it looks like you don't have?
I have a 4spd from an 81 Skylark which should be numerically lower than a Fiero (or an X11). Should be around 2500 @ 75 MPH or so.
One tough part about living in Massachusetts, all this stuff is long gone.
If you want wrap around exhaust you'll have to get it off a Deville - I've heard the 4.1 front manifold actually flows better than later years, but the Caddy motors aren't at a power level to make a substantial difference.
For your injector holes, 2 straight forward options depending on how you want it to look. 1 - leave the Eldo fuel rail and injectors installed and not worry about/ confuse people at car shows. 2 - get an intake off and 80s 4.5 Caddy, mine is from an 88 Deville - but there is a catch, they use different valve covers. The multiport intakes have covers that inset for the injectors and won't work on the TBI Caddy intake so you'll have to get valve covers to match the intake. If you wanna be super trick, use the holes for nitrous or you can go the get it done route and JB Weld dimes in the holes..!!
So I see Aces actually makes an MPFI universal setup. I wonder if that could run the 4.9 if I used a 'chevy' style TBI unit without any injectors. You used a factory 4.1/4.5 distributor with the Aces you installed, and the aces works with it? I'd be very interested in reading how you wired that. It looks like the 4.9 7 pin setup is useless with aces/holley, but if I can use a 4.1/4.5 setup, I'll go grab used one.
FWIW I've done a couple of Snipers and a old "terminator" setup (before they were snipers) on my F100, but the price of the aces makes it very attractive.
working on mounts right now, nothing to see really, just a Turbo 400 mount under the engine so far. I did start a tiktok for this thing for laughs.
Have been following this thread closely. There's a lot of good info here for people looking to do or have done a 4.9 liter engine in their Fiero. While the Aces EFI will do the job most Fiero swaps use the stock 2240 ECM. The Cadillac 4.9 liter V8 Fiero swap maybe a bit dated but I believe it's still a good engine. It's lightweight, fits great, has loads of low end torque and it gets pretty decent highway mileage. I chose this engine on my convertible project because it's a very good engine for hwy cruising and fun driving around town. . With the right software editor you can shut off the VATS and do a pretty decent job of tuning the engine and transmission but on the electronic side you're already committed. so I assume the ACES EFI self adjusting quality was the reason you used it. Some swipes have also added a camshaft but the red line stays the same so I left that alone as to not affect the gas mileage.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
So I see Aces actually makes an MPFI universal setup. I wonder if that could run the 4.9 if I used a 'chevy' style TBI unit without any injectors. You used a factory 4.1/4.5 distributor with the Aces you installed, and the aces works with it? I'd be very interested in reading how you wired that. It looks like the 4.9 7 pin setup is useless with aces/holley, but if I can use a 4.1/4.5 setup, I'll go grab used one.
FWIW I've done a couple of Snipers and a old "terminator" setup (before they were snipers) on my F100, but the price of the aces makes it very attractive.
working on mounts right now, nothing to see really, just a Turbo 400 mount under the engine so far. I did start a tiktok for this thing for laughs.
I've been looking into the universal sequential port systems (Wild card and Joker) because I really want to use them with their trans controller for custom Cam and turbo mods, but there is a hurdle - Aces uses a 7 + 1 hall effect sensor to correlate cam timing to fire sequential port injectors. Short answer: the MPFI kits won't work with an HEI - I used a vaccum HEI with the TBI kit and it works ok, but is much better giving timing control to the Aces ecm. For the TBI setup, you just wire the two magnetic pickup wires from the distributor and set timing - then you can have ECM fire the HEI coil, but I would recommend you use the Aces coil and convert to remote mount. I'll post and update soon, but I figured out a remote setup for less than $10 in hardware plus a plug wire. Also, you can use any year 4.x distributor - I initially used a 4.5 because it was better suited to convert to vaccum advance, but then found it wasn't necessary, it runs much better feeding magnetic pick up to the ecm.
I talked to Aces about modifying a distributor to work with the Caddy motors, but won't happen for awhile if they do. I'm not sure there's enough market for them to offer a dedicated distributor, so I'm looking to modify a Ford distributor or if needed cut and weld 2 different ones together. That's how I got an LT1 PCM to run my modified 4.9 - welded an Opti spark onto the HEI and used a Coil per cylinder conversion kit to run LS coils.
I know its a ways out, but would be great if you have it done and can join the X-bodies at Carlisle next June.
Have been following this thread closely. There's a lot of good info here for people looking to do or have done a 4.9 liter engine in their Fiero. While the Aces EFI will do the job most Fiero swaps use the stock 2240 ECM. The Cadillac 4.9 liter V8 Fiero swap maybe a bit dated but I believe it's still a good engine. It's lightweight, fits great, has loads of low end torque and it gets pretty decent highway mileage. I chose this engine on my convertible project because it's a very good engine for hwy cruising and fun driving around town. . With the right software editor you can shut off the VATS and do a pretty decent job of tuning the engine and transmission but on the electronic side you're already committed. so I assume the ACES EFI self adjusting quality was the reason you used it. Some swipes have also added a camshaft but the red line stays the same so I left that alone as to not affect the gas mileage.
You nailed it Dennis, Hwy cruising and fun around town! The self tuning is great, I've set desired air/fuel ratios in different places and it doesn't take long for it to correct the fuel table. For the Budget Beater Skylark I wanted to fix idle and AC input and figured it was the lowest risk (lowest cost) to get the Deuces Wild and see what Aces is like to work with. For me, saving time is a high priority and the Aces setup was up and running fast - I would say exceptionally fast compared to my OEM swaps. The wiring harness is a big part of that, I only hooked up 6 wires and was driving= Battery +, Ground, Ignition, AC input, Fan and Fuel relay control (later added added pick up wires). The harness has every wire labelled and has high quality mesh loom. I figured it saved multiple days of wiring and tuning a OEM swap (stock harness). I've always done the stock harness route before, but now this is the way to go. I have several projects in line and a move home to Florida next year so saving time is huge for me. I ended up ordering a full top end kit for the Turbo LS Olds Omega swap I'm doing next because at the price, everything included and bonus of saving at least a week on build time.
Another question. The 4.9L Cadillac V8 engine uses an idle air control motor to set idle speed. Its very different than what is used on most other GM cars. Your installation doesn't seem to use any IAC. How did you get around that? The 4.9L engine also uses a cam position (hall effect sensor) that may be critical to timing. When it goes bad, the engine runs like crud. Apparently you did not use a CPS or IAC.. What you did here with your swap is working but a rather complex, expensive and difficult approach. IMO its pretty hard to use an alternative ECM on this engine and get it working right but a few others have also done it.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Another question. The 4.9L Cadillac V8 engine uses an idle air control motor to set idle speed. Its very different than what is used on most other GM cars. Your installation doesn't seem to use any IAC. How did you get around that? The 4.9L engine also uses a cam position (hall effect sensor) that may be critical to timing. When it goes bad, the engine runs like crud. Apparently you did not use a CPS or IAC.. What you did here with your swap is working but a rather complex, expensive and difficult approach. IMO its pretty hard to use an alternative ECM on this engine and get it working right but a few others have also done it.
* It's Magic !! *
No, not really - it's in a well engineered throttle body - it has IAC, IAT and two 100 lb injectors built into it that you don't see. The Aces TBI units only need two sensors hooked up and they are both provided in the kit - coolant temp (use in stock location) and the Wideband O2. The harness has extra length wire for both. Given all needed sensors and inputs are included, it is very easy to install and have running in a weekend. It took me longer to plumb the new fuel lines and pump than it did the harness, ecm & throttle body. The Deuces Wild, High Roller CDI, AN fuel lines, new fuel pump and some hardware ran me just under $950. The CDI isn't needed, I just like running one, so without it this setup is about $800 ($850 if use Aces coil) for the kit and fuel upgrades - and it runs better than an oem Cadillac.
The 4.9s got a single prong hall effect sensor to sync the sequential port fuel injection - it tells the ecm when it's at #1 TDC, so it is not needed to run TBI and does nothing for ignition. Cadillacs run bad when the hall effect sensor fails because it defaults to a safe setting because the ecm can't see when the engine gets to #1. Aces uses a dual sync "7 + 1" hall effect sensor for sequential multiport injection, which uses evenly spaced gaps and 8 metal tabs on a shutter wheel. The #1 is half as wide as the other 7, hence "7+1". This allows the ECM to sync the injectors to the firing order. Ford used this setup in their DuraSpark for years which is why I'm looking to modify it to use Aces multiport system on a future project - it will give the best of all around performance, tunability and fuel economy.
The Aces systems come boost capable with wideband O2 sensors and are self learning, so for me it is a much better starting point/ build strategy. OEM swaps work, I've done several but they have challenges and short comings. I think the Deuces Wild kit is a great option for those that want to try doing the work for themselves but don't work on cars all the time. Its a cost effective option, even if paying someone because it is a fraction of the labor/time compared to making OEM stuff work.
I appreciate the questions, let me know what else I can share.
Cheers
[This message has been edited by 81 4.9L X-11 (edited 08-10-2025).]
Originally posted by 81 4.9L X-11: I've been looking into the universal sequential port systems (Wild card and Joker) because I really want to use them with their trans controller for custom Cam and turbo mods, but there is a hurdle - Aces uses a 7 + 1 hall effect sensor to correlate cam timing to fire sequential port injectors. Short answer: the MPFI kits won't work with an HEI - I used a vaccum HEI with the TBI kit and it works ok, but is much better giving timing control to the Aces ecm. For the TBI setup, you just wire the two magnetic pickup wires from the distributor and set timing - then you can have ECM fire the HEI coil, but I would recommend you use the Aces coil and convert to remote mount. I'll post and update soon, but I figured out a remote setup for less than $10 in hardware plus a plug wire. Also, you can use any year 4.x distributor - I initially used a 4.5 because it was better suited to convert to vaccum advance, but then found it wasn't necessary, it runs much better feeding magnetic pick up to the ecm.
I talked to Aces about modifying a distributor to work with the Caddy motors, but won't happen for awhile if they do. I'm not sure there's enough market for them to offer a dedicated distributor, so I'm looking to modify a Ford distributor or if needed cut and weld 2 different ones together. That's how I got an LT1 PCM to run my modified 4.9 - welded an Opti spark onto the HEI and used a Coil per cylinder conversion kit to run LS coils.
I know its a ways out, but would be great if you have it done and can join the X-bodies at Carlisle next June.
Sounds like I'm better off putting some freeze plugs into the injector holes for now and running a TBI setup. I'd love to go terminator but $$. I'm very interested in what you did ultimately (so I can do the same with my 4.9 ha).
Carlisle might be doable. Would be nice to meet Terry, Brad, and yourself.
[This message has been edited by psquare75 (edited 08-10-2025).]
Sounds like I'm better off putting some freeze plugs into the injector holes for now and running a TBI setup. I'd love to go terminator but $$. I'm very interested in what you did ultimately (so I can do the same with my 4.9 ha).
Carlisle might be doable. Would be nice to meet Terry, Brad, and yourself.
Cool, always welcome other enthusiasts!
Far as the freeze plugs, unless your trying to be super show car I'd leave the injectors and fuel rail - it won't hurt anything and you know they seal properly. Aside for the update I'll post next, I think everything you need to get it running with a TBI kit is in this thread - if not, hit me up. To clarify ignition, when you put the motor together set #1 TDC on timing mark and distributor - if it doesn't fire right away, rotate slightly clockwise. You'll have to do the TPS learn first and then once at temp use the hand held to "lock timing:" which is 15*BTDC and then use timing light to set distributor (unlock in hand held when done). When your ready, email me and I'll send you my working tune - will save you lots of time. The whole open tuning thing Aces does is one of the things I really like about their approach, it makes it possible for anyone to use a learned tune to run.... kinda like car guys put it together !!
I'm more anal than I care to admit, lol. I'm going to reseal this, do the baby Delta cam, and call it a day.
I'm guessing the software is similar to Holley EFI?. I do like the separate ECU. Never had an issue with either sniper I did, but the Terminator I did in my F100 has a separate HP style ecu I stuffed under the center of the front seat. Seems much more preferable. The 4.9 dizzy is the only thing really throwing me off.
I posted earlier that the FAST remote coil conversion kit fails pretty fast, no pun intended. I decided to try some stainless steel hardware and it works great. I checked after about a thousand miles and it is not a pile of shavings like the brass button was, so I'm confidant this is a good option. The best part is all the pieces were at Home Depot and less than $10. I used all stainless hoping to prevent the corrosion issue when different metals stay together without a protective coating.
I'm more anal than I care to admit, lol. I'm going to reseal this, do the baby Delta cam, and call it a day.
I'm guessing the software is similar to Holley EFI?. I do like the separate ECU. Never had an issue with either sniper I did, but the Terminator I did in my F100 has a separate HP style ecu I stuffed under the center of the front seat. Seems much more preferable. The 4.9 dizzy is the only thing really throwing me off.
If your wanting to keep the multiport and try an Aces Wild Card system, I'll help prototype the distributor. I want to have the solution soon, but I'm not in a position to work on another full 4.9 swap right now. I got my hands on a new DuraSpark this weekend and disassembled it to see what it would take to use it. It won't be as easy as say the remote coil conversion but I'm pretty sure I can make it work. I'm also waiting to hear back from Aces with dimensional info for their distributors to see if there is a better fit, hoping it gets to the right person because the Techs said I need to talk to an engineer...
Ok, cool - mount bracket looks good. What's your timeline for the build?
I ordered some aluminum stock to sleeve the dizzy shaft, should be in next week (4.X Caddy distributor housing tube is wider than anything else I could measure). My plan until the universe tells me different is to sleeve the Ford Durospark tube and drill new hole in the shaft for the Caddy length and cam gear. I'll plan to try it on my Skylark so we know it'll work ....
So I got the first hurdle handled - I took a couple of Caddy distributor gears to the machine shop and had them cut to fit the larger distributor shaft of the Durospark. The Ford distributor is taller/ longer, has narrower housing but uses a thicker drive shaft, which all lends it to modifications to run the Caddy 4.X motors.
I will cut the distributor shaft to match the Caddy length and drill it to use the Caddy gear. The next thing is to sleeve the Ford housing to fit correctly in the Caddy block. I’m waiting on some specific sized aluminum pipe - hopefully soon.
[This message has been edited by 81 4.9L X-11 (edited 08-28-2025).]
Yes, but with a qualifier - I'm just a guy that likes building cars, not looking to have a business making parts. That said, I'm happy to help others get their builds on the road. My primary goal is to find the most strait forward way to get it to work so others have the cheat code to replicate if they want, just enthusiasts helping each other.
One of the limiting factors will be Caddy distributor gears, they're like $80+ new so not looking to buy a bunch. You can get used distributors for $25-50 at local yards & pull the gear off. Once I get it working I'll make a couple extras and will ask whoever wants one to send me a Caddy gear and everything else will be new. Or if you want a new gear, that works too.
Cheers
[This message has been edited by 81 4.9L X-11 (edited 08-30-2025).]
I finally got the aluminum stock I ordered and it looks like it's gonna work pretty well. It'll be a week or so before I can get to finish and test it, but here are a few pics. The Duraspark dizzy has significantly less contact area on the housing compared to the Caddy, so I will use a sleeve as long as the Caddy's contact pads and spot weld on each of the widest points. The stock is 40mm OD and 38mm ID and fits in the block the same as a stock Caddy distributor.
The pics have a new distributor with the Ford ignition control module, but it will not be used - the Aces system only wants the 7+1 hall effect sensor signal.
Happy Labor Day
[This message has been edited by 81 4.9L X-11 (edited 08-30-2025).]
Interesting. This would open up other Ford distributors then, like a Dual Sync, or something that speaks Holley? I'm still here. Cam was sent off to Delta last week.
This Duraspark (2), Aces & Holley distributors are all Dual Sync and interchangeable. It’s the Hall effect sensor with 7 + 1 reluctor wheel that allows cam timing - the leading edge of each blade triggers spark (similar to but cleaner than an HEI), when the single half width blade passes the ECM know #1 TDC and uses firing order from there for multiport. Watching the aces videos, you can change the firing order so their system can be more universal.
Just looked up Holley Dual spark, they’re going for over $500…. I got the new Cardone distributor for $100 and the tube and gear machining are @ $50, so for those that can do the work this will be a much more affordable option. For needing one made, it would be covering time and shipping from there.
Interesting. This would open up other Ford distributors then, like a Dual Sync, or something that speaks Holley? I'm still here. Cam was sent off to Delta last week.
Nice! What’s the going rate on the cam now? Guessing they don’t have any new cores if you’re sending one in for reground?
They said $160. When I called I asked if I was the only playing with these anymore, the guy said no, they do them frequently still. I asked for the "one above stock that doesn't require headwork" "Ok! Send it in!"
We'll see what I get back. I still need to get a flywheel and a clutch but I dumped a bunch recently into replacement subframe, rear axle beam, rear discs, and more.
I don't feel bad about this public discussion which is getting long, as it is all ultimately contributing to this 4.9 cause.
This Duraspark (2), Aces & Holley distributors are all Dual Sync and interchangeable. It’s the Hall effect sensor with 7 + 1 reluctor wheel that allows cam timing - the leading edge of each blade triggers spark (similar to but cleaner than an HEI), when the single half width blade passes the ECM know #1 TDC and uses firing order from there for multiport. Watching the aces videos, you can change the firing order so their system can be more universal.
Just looked up Holley Dual spark, they’re going for over $500…. I got the new Cardone distributor for $100 and the tube and gear machining are @ $50, so for those that can do the work this will be a much more affordable option. For needing one made, it would be covering time and shipping from there.
I did a Dual Sync in my F100 but when I put that together 10 years ago that's all that was out, the Terminator with the NASCAR style throttle body, and a Dual Sync.Snipers didn't exist.
Honestly if this works out, I might spring for a Terminator ECU for my Cadillac setup and use a chevy TB with the cadillac injectors. The distributor is the last piece of the puzzle. The ECU would cost more than the drivetrain did, but I've been happy with mine, overall, in my truck.
