I have a 200,000+ miles 302 in a 86 F150 4x4. What is possibble to just drop into this truck? Is there anyway possible to change to diesel?

 

the 300 I6, 289 V8, 302 V8, and 351W V8 use the same tranny. basically they are all drop ins.

You would need to go totally custom on a diesel swap. I recommend you go with a 302, as that will be the easiest to get in there, and you won't have to go chasing wiring harnesses or computers.