8 3/4 rear end.
while back i seen a chart that showed rear end widths, the 62 to 63 8 3/4 housing for the b body, is same width as the a body housing, i have one, and measured it, the measure the same, width, the a body axles will bolt up easily, i moved the spring pads in 1/2 inch per side to fit a body springs. i use the a body 10 " by 1 3/4 brakes