Hey guy,
Its kinda easy and kinda hard all in one. If you have a PRE-95 there's no hope for the a/c box, I don't care if you have a/c or not, after 94 they went to a different box and everythings the same as the new styles. As for the rest its pretty straight foward. The SOHC and OHV share ALOT of the same stuff on the block, motor mount holes in the side are the same and the bellhousing bolts EXCEPT for the top passenger's side, its lower on a SOHC. I have 7 out of 8 bolts holding my transmission to the engine, I feel very secure with it. On the 98up 4.0 OHV's alot of the trannys have this hole in them on the OHV's so that they can be swapped with the SOHC on the assembly line. Simple stuff like throttle cable, water hoses, and if you use the new style computer you'll have to adapt everything to work with it on your previous style dash and under hood harness, still not too bad. The Y-pipe from the OHV even works but you'll have to open the holes up a bit to get it on the manifolds.
All in all its a pretty straight foward swap that shouldn't have to do much to. With an auto though don't forget that with each year came more and more changes so you'll need the auto for the year computer and engine you have. The manuals will interchange.
Mind you this is not a swap quide, these a just a few things. You'll still have a few things pop up but nothing too major, NO its not a weekend thing that should be done on your daily driver.
Later Doug904.