Does anybody have any information on weather I could put my v8 motor from my 2002 into my 1991 f150 and if I would have to use the 2004 engine harness?

 

It would require a lot more than just the harness. The PCM, the tranny, a whole pile of stuff

Not impossible, but you can 't just put the motor in and run it.

 

This is not a simple engine swap this will be a very involved custom modification, the modular engine from that 02 uses a much more complicated electronic control system that is integrated into many other vehicle systems so you would need the whole vehicle's wiring harness, dashboard and harness as well as the complete engine and transmission and then you would have to fabricate mounts for it all in the '91.

 

More specifically would I have to use the Pat's system or could I disable it I lost the key for it and don't want to pay to have a new one made the transponder that reads the key is broke also