COMP's Positive Stop PTFE valve seals offer more clearance for dual springs with better sealing than o-ring or umbrella seals. These 513 seals have a .600" outer diameter and fit applications with 5/16" valves and .600" OD valve guides.
Available individually under 513-1, available in a set of 16 under 513-16
Engines w/ 0.500" OD Valve Guides and 5/16" Valve Stems