351w H/C/I AFR 265cc heads (58cc chamber, 9.5:1) Crane Cam 444232 (originally intended to run the motor on speed density but realized I wouldn't be satisfied with that, this cam is supposed to be "computer friendly" for SD EFI) 1.72 ratio Scorpion roller rockers Edelbrock Performer EFI Truck intake Stock truck throttle body 36# Trick Flow injectors (@90% use at 5500RPM) Shorty Pacesetter headers 2.5" dual exhaust, manual cutouts, Magnaflow Tru-X Muffler T18 4 speed 4.10 gears
I intended to make a very high torque, low end truck motor that I could drive anywhere, any time very reliably. I succeeded in that. The truck is very driveable. I had no real issue getting the PIMPX ECU to work. I originally missed 1 of the jumpers for the distributor but figured it out in a minute. Had the idle tuned in about 10 minutes. I use this truck for sled pulling (competition pulling a weighted sled for distance, for those that don't know), as well as a "weekend warrior" type deal. I've owned this truck since 2010, and it was a stock farm truck when I bought it.
I'm so happy with the way this all turned out that I have another, more radical 351w in my shop that I'm putting in another truck that will be getting a PIMPX ECU.
Last Edit: Jun 22, 2020 9:30:22 GMT -5 by gnr22: Updated thread
I don't know that I've found anyone else in this forum doing anything else like this. I figured it would be beneficial for someone else to know this can be done. I've made a lot of people very confused when I've told them that the truck is still EFI. And I've made even more eat crow that told me there's no way any kind of EFI would be able to keep up. Guys with carb'd big block trucks get pretty upset when an EFI small block beats them.
Since this thread was started, I've now finished my other project, and swapped a different motor in this 89 F350. The motor that was in it was all stock bottom end. I never touched the bearings or rings. Thing had a huge ring ridge when I put the AFR heads on, but I wasn't going to pull it all apart and get it machined at that time. Most of the parts remain the same. Swapped to an F4TE roller block and a Howards 220225-12. Very mild cam. Great street manners and vacuum signal. Slightly more lift and duration than the Crane cam it replaced. I can tell it has a lot more bottom end torque than it did before. Put some cheap hypereutectic flat top speed pro pistons in it and forged rods. I intended on reusing the factory rods but one of them had an issue when I tried to remove the wrist pin so I just went ahead and bought new. Dingle ball honed the cylinders. Cleaned it up with a hose and GUNK spray. Nothing fancy here. Same AFR 165 heads, stock crank. Didn't have anything rebalanced or taken to a machine shop. It'll spin the 35s in 2nd gear pretty easily if you stomp the skinny pedal. Pretty nuts compared to before.
I had an absolute bear of a time getting the thing tuned afterwards. No matter what I did, it didn't seem to want to hold a steady idle, then I couldn't get it to restart when it would die. Thing would crank and crank and then you might get a sputter and a pop but wouldn't stay running. Finally walked away from it for a day and treated it like a typical no-start issue instead of a "trying to tune it" issue. Finally found that the IAC was bad and wasn't opening more than 30%. I'm sure this was the IAC the truck came with in '89. Not sure how long ago it went bad, but found it pretty funny that if it was bad this whole time, I had the tune good enough that I didn't notice. Replaced this and had it tuned up pretty quickly. Have been driving it around for the last month or so. Still a little bit of fine adjustment to do but overall, another success.