Pardon my ignorance, but who has the parts?
This truck has the 1 ton rear end which has the big 8 lug drums and is of the 'full floating type' with 5.14 to 1 gearing according to my 1959 chevy truck operators manual.
I have seen patrick's gears, etc, for a 1/2 ton, but that series has a different diff. and I didn't see any gears available for my truck.