Hmm.. wonder if this is the same one I'm thinking of.
I did it on my last MJ, but also did a motor swap at the same time.
It's a straight forward swap. You'll have to address the driveshaft as they are all different lengths. Also the MJ never came with a NP242 (thats what I put in) so the cross-member is kinda fun figuring that out if thats what your putting in.