you should go SOA since that is how the axle was in the GM, you will also have to go to a wider 2.5" spring n the front and also will have to out board the spring hangers.
you will also have to fab up some custom steering, I used 1 ton TRE's from Moog and a 87 K5 stabilizer TRE, I had to ream out all the mounts, but not hard to do, made my links from 1.5 .25 wall DOM; I've jacked my jeep up off my stteering links.
Blue torch fab has a kit to swap a Chevy 44 into a CJ.