These VITON valve stem seals are the best you can buy ensuring great sealing under extreme heat in performance engines. These seals are a DROP-IN replacement for the factory seal and feature the "hat" design to locate the valve spring exactly like the OEM seals. Note the blue top on these seals that indicates the specially manufactured VITON rubber seal specifically made to fit:

 

 

Sold as a complete set for one engine containing 16 VITON seals