Description
If you’re pushing your engine beyond stock limits, OEM valves and springs become your weak link. The PROX 28.SIS3408-2 Valve and Spring Kit replaces those components with hardened steel valves and premium chrome vanadium springs engineered to handle sustained high-RPM operation without fatigue or premature wear. This is a direct bolt-on upgrade that uses your existing retainers and seals, making it an efficient path to improved reliability and performance in forced induction or high-revving applications.
- Nitrided steel valves
- Increased durability, reduced wear
- Chrome vanadium valve springs
- Designed for high-RPM stability
- Stronger spring rates included
- Accommodates heavier steel valves
- Bolt-on installation
- Compatible with OEM retainers
- Compatible with OEM bases
- Compatible with OEM seals
- Intake or exhaust configuration
- MPN: 28.SIS3408-2
