Assembled; Pontiac 455 Cubic Inch Engine; Aluminum; 215 CC Intake Port/ 175 CC Exhaust Port; CNC Machined 87 CC Chamber Volume; 2.11 Inch Intake Valve/ 1.66 Inch Exhaust Valve; 1.46 Inch Spring Diameter; Single; With Valves/ Guides/ Seats/ Springs For Hydraulic Flat Tappet Cam; Not For Sale Or Use On Pollution Controlled Vehicles