Moving rear end back

A member on here (guy with the purple cuda sorry it slips my mind at the moment) spaced his 1". It was on a 67 cuda. He used solid aluminum which of course is lighter. It set the rearend perfectly in the center of the fender well. You will have to remove the front hanger bolts and use longer ones for the bolts to be long enough. I was wanting to do the same thing but never got any further with it. The only question I had was moving the drive shaft yoke at the trans out of the trans 1" would be ok? It would lose 1" of full engagement to the trans therefore in my mind making it weaker I suppose.