I picked up a 91 F250 that had a 460 in it (still has E4OD) and will be installing a 85 351w with a C6 that I have kicking around (also converting to 4x4 in near future). I had planned to leave the 351 carb'd, but was wondering if the 460 computer would work to convert it to EFI. It still has the wiring harness (or at least most of it) and using EFI would save me from having to change the fuel system. I need to replace carburetor (currently electronic feedback) and I was thinking about picking up a Holley and 'performer' type intake, so I can just as easily pick up a complete 5.8 EFI intake and related parts instead...but the 5.8 computer and wiring are harder to track down.

They are both Speed Density with bank fired injectors, so I would think it should be quite doable as long as the injectors were the right size and fired at the same time. What injectors would have been on the 460? I have heard they were 24's.

Anyone see any major reason it shouldn't work, aside from having to deal with the trans wiring?

 

It will work but it will run rich because the 460 does indeed use 24lb(Lt Blue) injectors and because the computer is programmed to feed 7.5l of course. An early 5.8 EEC for a manual or C6 auto would plug right in and deliver better overall performance with 19lb(orange) injectors, this would also eliminate the need to fool the 460 EEC into thinking the E4OD is still present.

 

Thank you, that is about what I was thinking. Would you happen to know the code or part numbers for a 5.8/c6 computer that should work?

 

EEC box codes for a 5.8 with a C6 or manual include 8QJ, D9J2, E9C, E9C1, E9D1, 39D1, 8QF, 8QN, A2Z, C1Z.

 

Cool, thank you. I will keep an eye out for one. Is one tuned for more power than another or do they all have the same basic mapping?

I am still on the fence about converting the motor to EFI or just going with a performer style intake, 600 cfm holley and a good cam. I will be using this truck for dump/scrap yard runs and it will not likely get over 60 mph and not be in a DD status. I want to put as little money into this as possible and I have a decent 'inventory' to use up.

 

I just picked up a complete intake, wiring and computer from what I believe was an 89 truck. I noticed the wiring is quite different between it and both of my 91's. Are there wiring diagrams online or? so I can trace down what is what?