Assembled; GM Big Block Engine; Aluminum; Straight; Rectangular 358 CC Intake Port/ Round 125 CC Exhaust Port; 119 CC Chamber Volume; 2.3 Inch Intake Valve/ 1.8 Inch Exhaust Valve; 1.54 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