ISKENDERIAN Racing Springs Part Number 6105 Dual Valve Spring Set Of 16 Product Features: Engineered For Street Or Race Applications Drop In Installation Wound From Chrome Silicon Wire Processed For Maximum Durability And Performance Specs: Outer Spring : 1.430" OD / 1.005" ID Inner Spring : 1.005" OD / .730" ID Seat Pressure : 135 lbs at 1.812" Open Pressure : 315 lbs at 1.260" Rate Per Inch : 330 lbs Coil Bind At 1.260" Max Net lift : .550" ALL Isky Products Are MADE IN THE USA !!! Message Us With Any Questions See Our EBAY STORE For Your ENGINE And PERFORMANCE Needs