Edelbrock part #5794 Sure Seat Valve Spring Kit is designed for Small-Block Chevy O.E Cast Iron Heads. Made of highest quality spring wire and precision wound to close tolerances. This Sure Seat Valve Spring set is for use on original equipment heads when installing Edelbrock Performer-Plus camshafts. The valve springs are designed for use with OEM valve rotators. For camshaft warranty compliance, use only the springs recommended by Edelbrock for each camshaft application. Set of 16. Valve Spring Specifications: Type: Non-Rotator Seat Pressure: 110 lbs. Installed Height: 1.700" Open Pressure: 285 lbs. @ 0.490" Outside Diameter: 1.265" Inside Diameter: 1.060" Coil Bind: 1.160"