The "Red Stripe" spring is the strongest 10.8 lb spring on the market. This Heavy-Duty spring will allow the engine builder to custom fit their spring to their particular build. Having been through a specific process, which will reduce the amount of spring pressure loss from running in the engine, this spring will allow the engine to run a higher RPM before experiencing uncontrolled valve float.
This spring is considered a "Builders Spring" and will not test legal without being set. Springs should be checked prior to installation to ensure they meet rule requirements.
Spring Pressure:
11-11.5lb @ .850" installed height
19-19.5lb @ .650" installed height