The Edelbrock #61579 Performer Pontiac Cylinder Head utilize a D-Port exhaust port configuration for use with standard D-port exhaust systems. They are designed for 1962-79 389, 400, 421, 428 and 455 c.i.d. V8 Pontiac engines with a 4.060 or larger bore. Product Features:Complete Single For Hydraulic Flat Tappet87cc Combustion Chamber Volume204cc Intake/145cc Exhaust Runner Volume2.11 in. Intake/1.66 in. Exhaust Valve Diameter0.625 in. Deck Thickness
