8.8 swap
If you center the yoke you'll be off 1-3/4" from stock A-body specs as their yoke is not centered. It's off center to the pass. side 1-3/4".
Also how are you going to bolt up that U-joint to the flange that's on the rearend now? Won't you have to swap the yoke for a conventional style? If so why not just get a conventional 7260 yoke so you don't have to run a conversion U-joint?