A-body 8 3/4 axle housings are all 52 5/8” wide. That’s just the width of the housing.
A-body 8 3/4’s with small bolt pattern axles and brakes are 57 1/8” drum to drum, or more specifically, wheel mounting surface to wheel mounting surface.
If you install BBP axles and brakes, the drum to drum is more like 57 13/16”.
It really depends. You could just make it A-body width, so, the housing would be 52 5/8”. But what I would do it pick the wheels you want first, because they may not be available in a backspace that works with a stock width A body axle. Then you just make the axle the right width to use those wheels.
And if I was narrowing an axle, I’d do the 1/2” spring offset. You’ve got to weld on new perches anyway, might as well gain some tire space.
Yeah but you don’t bolt your wheels to the housing
