Assembled; Pontiac 6.4L-7.5L/389-455 Cubic Inch; Natural Aluminum; 195 CC Intake Port; 145 CC D-Shape Exhaust Port; 72 CC Chamber Volume; 2.11 Inch Intake Valve; 1.66 Inch Exhaust Valve; 1.46 Inch Spring Diameter; Single; With Pushrod Guides; Rocker Studs