XJ to MJ rear axle swap? (D30)

I have a '87 MJ (Comanche) Long bed 2wd that I just got, and want to do a buget lift, and change to 4wd. I have tranny, TC, front & rear axles from a '86 cherokee that I parted a few monthes ago. I can get past everything on the drive train with bolt-on but today I mesured between the springs on my MJ and on my '92 XJ and the MJ mesured about 1.5" narrower. The thing is the XJ is spring over and the MJ is spring under, which would yeld about 3" lift, and I heard F150 front coils will give about 3" in front. My ? is about the track width between the rear XJ vs MJ?

Sorry, it's a D35C rear

it'll be more than three inches measure tube,perch and spring thickness cause its all going to be reversed (~5.5 or so)

Thax for the info. Know anything about the difference in width?

The MJ's have the "frame" under the box, and the leafs are mounted inboards of the rails. With the XJ's, the leafs are mounted outboards further. Hence the perch width differences.

You will have to cut and move the spring perches. Since you're moving them anyway, it's a good time to set the right pinion angle instead of mucking with shims later. As I recall the perches moved in 1" each side when I did it. The SOA yielded 5.5" of lift in the back. I used a 4.5" kit for an XJ that had front springs, LCAs, track/swap/brake drop brackets, and (4) shocks. I think it was a Rough Country brand that I got for $330 from an eBay vendor. If you move the shock mounts up to about the center of the tube, you can use XJ 4.5" lift shocks (and they don't catch rocks anymore). With fresh springs up front and the slightly sagged rear springs it's sitting about 5" taller than stock.

What I have is '87 MJ spring-under rear D35C stock, I have a D35C XJ spring-over rear axle w/perches on top, I was hoping to just swap axles and get SOA lift. looks like I need to move perches anyway, but will still use both XJ axles so as not to change gears, since I'm changing to 4x4 anyway and need to install font axle and want to keep same gears front and rear.