Darrol, an 80 J10 360 motor is an AMC (American Motors Corp.) motor, not a Mopar 360. Nothing between the two will interchange. The AMC 360 was a good motor, but I suspect some parts may be tough to find.
As far as the transfer case is concerned, I would stick with what was originally there. During that time AMC was buying many major parts from several manufacturers, as a result of this many AMC parts may fit only a year or two, or a specific trans, or rear end, or whatever. Swapping stuff through AMC will become a basket of worms real quickly, few really knew what interchanged, and finding that accurate info these days may be a real challenge.
As an example, back 20 tears ago I bought a pair of J10 Jeeps, one was a heavy duty 78 and the other was an 80. There were no parts that interchanged, except the snow plow brackets I moved from the clapped out 78 to the clean 80 body. The 78 had an AMC 360, but 80 had an unknown V8. The 79 had a GM trans, the 80 had a 727. The front driveshaft on the 78 was on one side of the trans, but the 80 was on the other side, so the transfer cases didn't interchange, front axles did not interchange, transmissions did not interchange, the exhaust did not interchange, and neither did the radiators. I ended up putting a 318 in the 80, and it was a major challenge for me at the time. I sold both J 10 a few months later (less the plow). Don't miss either one. Gene
