Not exactly following you.

I did look at using the rear axle assembly out of my 2wd truck in my 4x4 (both 1986 models). I didn't do it because of the work involved. It wasn't much, but just wasn't worth doing for me. The problem wasn't in bolting the axle onto the spring, it was the rest of the stuff. Frame mounted bump stop, different e-brake design, etc. The match up to the spring itself is just fine though.