Have you pulled a drum to check your brake type? All of the 52 3/4 ton trucks that I have seen had bendix. I'm not saying you don't have hucks, just wanting to be sure you know what you do have. You can get the brakes from a 3/4 or 1 ton with bendix, you need everything from the backing plate on out. They will bolt right on.
There was a guy who converted to a disc setup and used cold-rolled steel for his brackets, which is not recommended. No one makes a conversion for these trucks, I wish there was one. There is and outfit in Texas that does some sort of high friction lining on shoes, but they aren't cheap.
From my experience with the 3/4 ton, there is enough braking power with the standard bendix brakes for highway driving in an empty truck. My 69 1/2 ton came equipped with the same size shoes. Loaded, I don't go much over 40.
