[56don]

I have a 56 Chevy with stock rear brakes and 72 Monte Carlo front discs.I just got a MasterPower 9" power brake and master cylinder unit for it.Will an adjustable proportioning valve on the rear be all I need or do I need to use residual valves on it also?

[willys36@aol.com]

Drum brakes need a 10psi residual check valve to precharge the system so it will perform properly. Disk brakes usually use a 2psi check valve. OEM master cylinders have these valves built in. I am not familiar with your master cylinder, but if it doesn't have the check valves, you need to add them in your system.