Rear Axle

I think you will find all A body rearends are the same width. Regarding the driveshaft it will probably have to be shortened because the 8 3/4 center section (third member) is longer. Also there are two sizes of yokes small and large. All the A body rearends I have seen came with the small yoke. However Its possible you may find an a body housing that has a third member with the larger yoke for the u joint that will not work with your driveshaft even after shortening