Hey, I've got a 1985 F150 Shortbox Flareside with the EFI 302. What I'm hoping to do is swap out the entire Truck wiring harness, computer and engine, and swap it with a 1990 H.O. 302 out of a '90 Mustang. I have the mustang engine, computer already and I'm getting a wiring harness from painless. I'm planning to rebuild the Mustang motor to get a few extra ponies (chip the computer, heads, etc.). I've been told it's rather straight forward to swap these since the truck computer and wiring harness runs strictly the engine, and the mustang wiring harness supposedly runs just the engine as well. Painless tells me they can run that engine in a shopping cart and everybody else is telling me it's just plug and play. Is there anything else that the mustang computer runs that I need to worry about?

 

Moved from 2011 F100 forum.

 

Yes both vehicles have stand alone engine management systems, and with only a few exceptions the truck harness is identical to the car harness(the early EFI truck may have additional discrepencies). Those exceptions include the sequential injector and maf meter wiring, a drivers side O2 sensor, and canister purge solenoid.. all of which the truck doesn't have. In addition there are a few sensor/actuator wires that are on different pins, the TAB and TAD solenoids for sure and there may be another one but I can't remember at the moment.

 

Thanks Conanski, So if i were to enchange the computers and convert the wiring to a MAF i should be able to run the Mustang engine? Or would I be further ahead to change the entire truck harness to the mustang harness like i had thought before? I'm totally new to this conversion so it's only beginning to make sense to me

 

Actually you don't need to change any of the wiring or the computer to run a stock mustang 5.0, just bolt it in there and hook it up. It won't take much hodrodding on the HO to exceed what the truck computer can control however, so it may be just-as-well to get it done now. It's less work to just add the wires you need to your existing harness IMO, the mustang harness is built completely backwords compared to the trucks because the computer resides in the passenger kick panel.

 

All you should need is the intake with all copents, harness, ecu

 

If you use the truck computer dont forget that you will need to do some swapping of the injector connectors as the H.O has a different firing order then your truck does.

 

Thanks for the help everybody, after looking into the mods that i wanted to do to the mustang engine, my dad and I have decided that it's going to be easier to do away with the efi harness and run the mustang engine with a carburetor. I still plan on running the truck engine for a few years until i get this other engine completely rebuilt and ready to put in. Chances are, I won't have to worry about it for a little while now since i only work part time after school and I'm looking to get a set of AFR heads for this engine, cam, intake, carb, etc..so it shouldn't be for awhile. I hadn't planned on going this far with the engine before this though lol. Thanks again for the help everyone.