Part# ET255 DUAL 128# .490” Lift ECOTEC, Drop In, Dual Racing Valve Springs: 253# at Max lift (.490”), Drop In Racing Valve Springs, using stock retainers and w/our valve seals and shims kit, without any Machining required. These springs are compatible with all Ecotec 2.0, 2.2, 2.4 liter Ecotec engines. Specs: Part Type: Ecotec Drop-In Racing Valve Springs. Compatible with all Ecotec 2.0, 2.2, 2.4 liter Ecotec engines Type: DUAL Damper Included: No Outer Spring Out Side Diameter (O.D.): 1.010" Outer Spring In Side Diameter (I.D.): .740" Seat Pressure: 128 @ 1.320” Open Pressure: 253 @ .830" Spring Rate/Inch: 250 Maximum Suggested Lift: .490" Coil Bind: .830" Electro Polished: No Nitrided: No Suggested Steel Retainers: VSRET252-B Manufacturer: Racing Engine Technologies Manufacturer's Part Number: ET255DUAL Packaged Weight: 3.0 lbs. Warranty: Race Application, No warranty expressed or implied Quantity: Sold in Sets of 16