I have a 75 F-250 2wd right now that I plan on converting to 4wd at some point (not any time soon). I am not all to familiar with Ford's to be honest. The truck has been sitting for some time, started it the other day and it has a rod knock. I have found a pretty decent deal on a '78 460 with all accessories and electronics. I am not sure what trans is in the 75 at the current moment but the 460 was bolted to a c6. Do the 390 and the 460 have the same bolt pattern or are the bell housings on ford trasmissions interchangeable? What would I need to make this swap?

no 460 and 360/390 are diffrent...your gonna need a diffrent trannsmission.

No, bolt pattern is different, 390 is an FE series and the 460 is a 385 Series motor. Motor mounts and transmission will be different

You're looking for a C6 from behind a 351M, 400M, 429, or 460. Lots of cheap 351M powertrains out there, if ya look. Go ahead & get it now with a 205 transfer case on the back & save yourself changing the trans again later.

I just picked up a couple of 'em for projects for $100-150 respectively for C6 bolted to a 205.

I see you're in MI, so I am I. If you're interested in a Ford 3/4 ton 4x4 frame with axles PM me.

check ebaymotors they sell some nice conversion mounts for 360/390 to 460 i used them on my build, they work nice.