thanks for the replies. There is a guy that I've met that has a MJ Comanche with a 12valve cummins 5.9. It is a monster. Not only is it a cummins but a built one. That's where I got the idea. I rode with him through his field where he has bulldozed himself a nice obstacle course and let me say 500hp and 750 ft lbs feels good in a MJ 5" up with 36" SSRs. So I know it will fit and I know it is possible so this is still a possibility. A local kid here has a 89 cherokee with a 400 sb chevy with about 425hp and all he did was weld in some frame strengtheners, and has had that set up for a couple years. I have to disagree on the XJ platform. Sure the unibody isn't ready for a hardcore comp rig but, my family likes to go wheelin too and you can't beat an xj for good comfortable wheelin down a skinny quad trail with the wife and kids. If I was gonna build somethin to ride on 54" michelins, I would worry about a frame but the old XJs haven't let me down yet. I might be tradin for a 77 K5 blazer with 39.5 boggers though, thats gonna be a fun project, because I don't mind cuttin and weldin on a junkster. I have been wanting to put these rockwells and some commercial michelins on something since i bought em.

back to the XJ.... that cummins idea is sounding better and better now that I think about it.