8 3/4 rear ends

They will be to wide for your A body. E and C bodies are the widest of the car rear ends. 71-74 B bodies are to wide also. As mentioned the early B bodies 65-67 will work and are just a little wider than the A- body 8 3/4's. Stay away from 64 and earlier rears as they used a 2 piece taper axle. Of course the bolt pattern is larger on a B than a A-body.