COMP's Positive Stop PTFE valve seals offer more clearance for dual springs with better sealing than o-ring or umbrella seals. These 512 seals have a .600" outer diameter and fit applications with 3/8" valves and .500" OD valve guides.
Available individually under 512-1, available in a set of 12 under 512-12
Engines w/ 0.500" OD Valve Guides and 3/8" Valve Stems