Convert my 2WD to 4WD

1987 Comanche
4.0
Auto Tranny
2WD

I have the jeep above and i am trying to make it 4wd. I know a few people with jeep cherokees they are pretty much parting out but im not sure exactly what i need for parts. I have an incomplete front end out of a 91 cherokee. I got the front differential with gears but am missing the right passenger side shaft. So with that i need the new shaft, transfer case, and the front shaft. I know the wheel base is different on the cherokees so i am assuming i will need to modify my drive shaft. I also heard that i might need a different transmission as well?

Any input would be appreciated, thanks.

need a new transmission as well if you are lazy, or the tailhousing, wiring harness, and output shaft from a 4wd transmission if you aren't (you'll have to fully disassemble the transmission, swap output shafts, reassemble, and swap the tailhousing and wiring harness over.)

You have an 87, so your donors would be 87-90 for exact numbers-matching drop-in or 87-95 otherwise. 91-95 will be easier to find spare parts for, and probably in better shape.

You'll need a new (or retubed/shortened) rear driveshaft (use yours, since the Comanche driveshaft is so long it's much larger in diameter to keep it from wobbling) and the transfer case shift linkages and handle, too. The rear driveshaft is the only MJ-specific part, the rest can be pulled from XJs.

Also, you're not that far from me! Let me know if you need help when you start working on this, I'm usually down for some wrenching if I'm not in the office.