Proportioning Valve: 79-81 Disc x 4 NOS - GM New Old Stock - SOLD OUT NO MORE GM NOS GM - These are

NOS GM - These are new GM # 549947

If your changing your compressor

At this price you can afford to keep the car in good nick

They are ok but not the high quality of the GM ones but at 20% of the price

Proportioning Valve: 79-81 Disc x 4 NOS - GM New Old Stock - SOLD OUT NO MORE GM NOS GM - These areSOLD OUT late 2025 but a REPRODUCTION Available. Last of the Genuine factory 4x Disc GM Proportioning Valves Till this last stock is sold only. Good alternatives are the reproduction PV's. For Firebirds & Trans Ams from 79 81, Carby or turbo.. with Factory Disc Brake rear end.. fits all the engine sizes, 301,400, 350, 80 Turbo & 403 etc. This is NOT for the Drum brake rear that one is listed elsewhere. What does a proportioning valve do? A