Wilwood's GM style proportioning valve is a direct replacement for 1978 and newer General Motors vehicles equipped with front disc rear drum brakes. Manufactured from high quality aluminum and coated with a durable black anodized finish. Line connections for the valve, if mounted in the OE location, Will allow the original lines to connect directly to the valve. If mounted in a non - OE location, fluid lines may have to be modified. This also does allow usage in other non - GM vehicles. This proportioning valve offers 63 pressure reduction (rear) after 350 PSI knee point. A 30 PSI delay rear - to - front circuit and circuit failure sender activation at 50 10 PSI. A Recommended maximum operating pressure 2000 PSI. Non - adjustable front - to - rear proportioning (knee point, rate, etc.) and Anti - dive or metering delay valve Enables rear brake pressure to build momentarily before front brake pressure builds.