yes it can be done. The more common swap is a 5.0 (302). I have a friend who is planning a 4.0 SOHC swap (2nd gen explorer) into an 84 Bronco II.
If you have the complete donor vehicle, you should not need many additional parts when you do the swap. I assume you will be doing the swap yourself, so the cost won't be bad.
Now if you are talking a shop...that's a whole different ballgame. There is a ton of wiring, sensors, the computer and everything else that has to be moved. I would bet that the drive shaft (s) would need to be custom made too.
What transmission do you plan to use? That would govern the transmission mounts and shifting linkage.
If you get into the swap and need specific help, contact the guys at ranger resource.
ranger resource. net