Wheather you need them or not also depends on where the master cylinder is related to the wheel cylinders. On a small street rod, the wheel cylinders can be higher than the master cylinder and thus, the fluid runs out of the cylinders back to the master. The pressure valves or check valves hold pressure in the cylinders. 10 psi is not enough to hold the shoes out if you have good springs and hardware. Just use parts from a modern truck about the same weight and you should be fine. Joe
