You might check out Jim Carter's part ME131, '46 - '52 rear. On the other hand, I found wheel cylinders for my '53 one ton at the local FLAPS. Still pricey, but less than the specialty resto places. The tricky part is finding parts numbers that aren't GM specific.
Tim
I am currently digging back in to a 1953 3800 (one ton) with a nine foot bed. I've owned it since 1979, and drove it until 1982 (or so). My wife got me involved in restoring it back in 2002, got the body removed and the frame redone, then things came up. Now I am retired and starting again. If anyone is interested I have photos on Imagur (
https://timwhiteblues.imgur.com/ ). I live way back in the woods in the Ozarks on 40 acres at the end of a 2 1/2 mile private road.
Tim
