Hey. I was looking into doing the same thing it involves alot of work. You pretty much need a whole donnor vehical. You need to sawp the motor the wire harness, the transmisson. I have read that you can use the 4 banger transfer case but you need to swap the input shaft, motor mounts. Um fuel line if its a 1990-1992 tb , you need to swap the the fuel pump. And if your donnor veicals not a yj i 98% sure that you need to get drive shafts lenghting or shorting. I have decided since i know my fare share about ford efi i'am goign to swap in a 302/ho/aod. I think its going more simple this way
Just my 2 cents