This is from mjeff87 concerning the 2WD drive shaft:
"Also, on the rear shaft.....those "tube-in-tube" style shafts were used on 2WD drive MJ's (I can't say exclusively, but I've never seen one on a 4wd MJ). They really can't be cut down to fit because there's a rubber isolator/sleeve inside the 2 different tubes at the yoke ends. If I had to wager, I'd say it was a 2WD shaft, and it's too long. For the front shafts, there's at least 3 different sizes of them as well, depending on what transmission was in the vehicle it came from. Each trans uses a different length shaft. I want to recall from memory that the AW4 was the longest, AX4/5 were the shortest, and the AX15/BA10/5 are intermediate length between the two."