Assembled; GM Small Block Engine; Aluminum; Straight; Rectangular 220 CC Intake Port/ Square 67 CC Exhaust Port; 64 CC Chamber Volume; 2.08 Inch Intake Valve/ 1.6 Inch Exhaust Valve; 1.295 Inch Outside Spring Diameter; Single; With Dual Valve Springs/ Damper Spring/ Retainers/ Locks/ Guide Plates/ Rocker Arm Studs/ Valve Stem Seals/ Valve Guides/ Valve Seats