Hi everyone,
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.
https://www.fiero.nl/forum/...148505.html#lastpost 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
50 Oldsmobile OLDS V8 HEI Distributor 260 307 350 403 455 Engine 1968-1976
** Moroso 72300 Advance Curve Kit, Fits GM HEI Distributors if you want to change advance curve
4 M8-1.25 x 30mm cap screw and (2) M8-1.25 x 45mm flat head machine screws Home depot
$834 Total
Trans converter lockup control
44 Superior Transmission Parts Vacuum Switch Kit A444428
www.amazon.com/dp/B072LT1VV..._dt_b_fed_asin_title 20 Double relay (ground for 3 and 4th)
15 Delay relay - adjustable up to 10 seconds of delay so the converter does lock immediately on shifting
8 LeMotech 5 Pieces Plastic Project Boxes Junction Case for Electronic Project, Black 3.1 x 2.0 x 1.0 inch (80 x 50x 26 mm)
$87
