Back spacing on B body rear end in 73 Duster

Good post, I just did this 2 days ago, haven't installed wheels yet, still waiting on parts to arrive and to set up the diff. I put in a 66 B body that is supposed to be the narrower of the B body rears. :blob:

5/16" per inch on each side. So figure a ~5.75 BS to get the wheel centered.