Not sure, but...
That is a pretty sweet deal, you could sell or use the tranny, motor, t-case out of that for spare cash or just spares. I am thinking of getting a XJ in better condition to swap all my nice parts onto, since corrosion is eating mine. Good luck with your project. I have heard that you do not want to large of a shckle in the rear...wears out the leafs springs from axle wrap I believe. I would maybe just look for a new set of rear springs?
2004 WJ Laredo-4.0L-Amsoil Synthetics-K&N FIPK-Borla Catback with Hi-Flow Cat-2" RC BB JKS Track Bar and Frt BPE, ADDCO Rear Sway Bar Future: RC Long Arm 4"