Viton valve seals with a reduced outside diameter are ideal for those that use double valve springs or may have problems with valve spring loose or simply have to install new valve seals due to worn parts.

Seals (Viton) have a temperature range of -5 ° to 450 ° F, which makes them one of the best available high temperature seals.

Viton has good flexibility, like nitrile, which means that it can handle some beating between the valve stem and the guide.

It is also considered a more durable material than silicone.

Viton also has better wear resistance than most other sealing materials, which makes it a good choice for applications where long-term durability is a must.

Fits:SUBARU EJ20 / EJ25 WRX / STi Turbo DOHC / Impreza WRX / STi

References:

Fits intake valves