Available individually under 503-1, in a set of 12 under 503-12, in a set of 16 under 503-16
COMP's Positive Stop PTFE valve seals offer more clearance for dual springs with better sealing than o-ring or umbrella seals. These 503 seals have a .630" outer diameter and fit applications with 11/32" valves and .530" OD valve guides.
COMP Cams offers a complete line of valve stem Seals, from the stock GM "O-Ring" to the positive-stop PTFE Seal. These Seals are a must to keep unwanted oil from entering the combustion chamber through the clearance in the valve guides. The "O-Ring" Seals use the standard retainer and oil splash shield. The umbrella Seal is normally used when a larger-than-stock diameter spring is used, in the case of a double spring, the positive-stop PTFE Seal is used. We also have a smaller diameter Viton Seal available for triple spring Applications.
