I did this on mine. I replaced the 8.75 with a dana and had it narrowed as much as you physically can narrow it for an a body with a relocation kit.
This will allow up to a 3.5" back spacing regardless of the width of the wheel.
If you narrow too far the leaf spring will hit the calipers (if you run disc brakes) My leafs clear the calipers by about a 1/4".
