Hy VEW, if your brake system is from the 1953 to 59 truck as we figured in your other post, then a master cylinder with a 1 1/8" bore would be sufficient. Your F.L.A.P.S. should be able to get you Raybestos p/n MC36246 which is a drum/drum master cylinder and would require no external residual pressure valves, hope that helps.