Spring Seats .570 ID (16) For RPM Duals Valve Spring Locator - Inside - 0.060 in Thick - 1.270 in OD - 0.570 in ID - 0.680 in Spring ID - Chromoly - Set of 16

Spring Seats .575 ID (16) Valve Spring Locator - Inside - 0.060 in Thick - 1.270 in OD - 0.575 in ID - 0.615 in Spring ID - Chromoly - Set of 16

1.324 Dual Valve Springs - RPM Series (16) Valve Spring - RPM Series - Dual Spring - 500 lb/in Spring Rate - 1.000 in Coil Bind - 1.324 in OD - GM LS-Series - Set of 16

1.290 Dual Valve Springs - RPM Series (16) Valve Spring - RPM Series - Dual Spring - 369 lb/in Spring Rate - 1.000 in Coil Bind - 1.290 in OD - GM LS-Series - Set of 16

1.304 Dual Valve Springs - RPM Series (16) Valve Spring - RPM Series - Dual Spring - 433 lb/in Spring Rate - 1.000 in Coil Bind - 1.304 in OD - GM LS-Series - Set of 16

1.324 Dual Valve Springs - RPM Series (16) Valve Spring - RPM Series - Dual Spring - 460 lb/in Spring Rate - 1.000 in Coil Bind - 1.324 in OD - GM LS-Series - Set of 16