Since no straight axle small trucks came with disc brakes, the caliper brackets will have to special made. My kit from Master Power brakes for the '37, uses early '70s GM rotors and calipers, one Ford bearing and one GM bearing with a special bearing adapter, and I think GM seals. The caliper bracket is special made to fit the straight axle spindles. I had to match the brake hoses to the calipers. The bolt pattern on the wheels is 4 3/4 on 5.
