7 1/4 width question....after searching
The 7 1/4 A-body rear ends with small bolt pattern are all the same from '63 through '76 except for some of the brake parts. Now, comparing the small bolt pattern 7 1/4 with the big bolt pattern.......I don't know. I haven't done that measurement, but, I doubt there's much if any difference since they came with the same track specs.