Endurance Plus Dual Valve Springs with Damper (16) 1.550" OD
220LBS @1.900" Seat Pressure, 530LBS @ 1.240" Open Pressure, 1.130" Coil Bind

The Endurance Plus series of valve springs utilises a specially processed Tool Room Material for increased endurance and reliability beyond the "SP" series plus special processing for increased durability. Endurance Plus springs are designed for late models, modifieds, etc and are Spintron Test-Proven up to 8400 rpm for 850 racing miles.