over the winter I did the same swap in my wife's '50 1/2 ton truck, I used a 12 bolt rearend from a '67 1/2 chevy truck, it was 62" wide, I also bought a 12 bolt 1/2 ton rearend from a '70 model chevy truck, it was 64" wide, but I just wanted the posi & gears out of it.
