hmm interesting i think u can get a YJ tub from quadratec.com gut there pretty xpensive, i know where u can get a CJ frame tho..... probably really cheap too
I just bolted a YJ body to my CJ frame today. It requires a little modification, but not much. The rear crossmember mounts are about 3/4 farther out on a YJ, and the 3rd body mount from the front on the sides is about 3-4" further forward on a YJ.
If I were you, I'd check ebay for YJ tubs. That's where I got mine. I read some bad things about the aftermarket steel CJ tubs, aluminum is really expensive, and I didn't feel comfortable with fiberglass.