any good A body junkyards?

Also you can use a 65 - 67 b body 8 3/4. I had both an A body an a early b body housing. After fitting both I used the b 8 3/4 because it is about 3/4 of inch on each side longer which actually looked better and gave me a little more room between the tire and spring and also you get the big bolt pattern axle and larger rear brakes. I did have the spring perches move 1/2 inch to be a perfect fit which only cost 60 dollars.
These rear ends are much more available and cheaper and the one I bought was a 742 instead of the 741 chunk.