Swapping out the rear according to Eric Zappe's book... Some MJ's came with Dana 44's, but they're sprung Leaf-Under, but are almost identical to XJ Dana 44's. Ford 8.8 out of a '95 or newer Explorer is 31 spline, .75" narrower and some later models have Disk Brakes. Caveat: these have had cases where the Tubes have spun on the center housing so they should be welded. I know the Ranger runs the same BP as an XJ soooo I'll assume the Explorer does too.
Front Dana 44: '80's or newer Wagoneer and Grand Wagoneer's, but they are 1" wider and are Leaf sprung. I think RE and some others have a conversion kit for Coils. But they are 6 on 5.5 bolt pattern, but they can be converted to 5 on 5.5. I don't know if you can change them to what we run, 5 on 4.5 and they're LOW-pinion!!!
Something to think about.
I'll try and remember to bring the book over so you can look at it.
Tattoo