rear diff width

Hello everyone,I was woundering if anyone knows the width of an 8 lug rear diff on their trucks? I have a 1950 chevy 1 ton and would like to put in a later diff to get rid of the 5:14s in the back, and better brakes. I would also like to keep the 8 lug so it has that 1 ton apperance. thanks Ron

14b sf on my side yard measures about 67" wms to wms. From a 3/4 ton diesel Burb with 13" drums.