"SP" Series Dual Valve Springs with Damper (16) 1.530" OD 150LBS @ 1.875" Seat Pressure, 435LBS @ 1.225" Open Pressure, 1.160" Coil Bind

The "SP" series utilises "Hi-Tensile" Chrome Silicon outer material. For applications with radical cams and/or moderately high rpm, where traditional chrome silicon springs prove inadequate, the "SP" series is the next highest level of endurance. All "SP" series springs are Spintron Test-Proven up to 8000 rpm for 700 racing miles.