Brad, I have a circa 1950 chev rear end in one of my chev 54s. Aside from
occasional annoyance on maintaining the huck brakes, it works just fine.
The problem you'll have in switching in a 50 GMC to your 54 chev 3100 is
that unless you've already changed to an open driveshaft, you won't be able
to use the open GMC with the 3100 chev tranny, made for a torque tube.
54 3100 (mostly all there)
54 3100 (mostly not there)
55 1st 3100 (mostly rust)
Los Angeles, CA
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959