Once more, with feeling-
THIS CHART IS GARBAGE!!!! :BangHead::BangHead::BangHead:
The majority of the dimensions it lists are
wrong. The A-body dimensions are completely wrong, the B-body dimensions are completely wrong, most of the numbers it lists are just flat out incorrect. Delete it from your files, stop posting it, let the damn thing DIE.
There's a great list right here on this forum
An accurate 8 3/4" rear axle width list
For the OP, a SBP A-body 8 3/4 is 57 1/8", an A-body 8 3/4 with BBP axles and brakes is about 57 13/16". So yes, about 11/16" wider for the whole axle, a bit less than 3/8" per side.