COMP Cams Valve Seals 3/8 Viton Metal B 521-12

Providing the best sealing properties and spring clearance, viton valve seals are an excellent choice in performance applications. The 521 seals have a .545" OD and fit applications with 3/8" valves and .500" OD guides. Available individually under 521-1, in a set of 8 under 521-8, in a set of 16 under 521-16 Engines w/ 0.500" OD Valve Guides and 3/8" Valve Stems