CYL HEAD PERF CNC D-PORT FOR PONTIAC ENGINES 87CC CHAMBERS SINGLE COMPLETE. The Edelbrock PN: 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. V8 Pontiac engines with a 4.060in. They feature optimized oil return passages for increased oil flow. The spark plug has been relocated closer to the exhaust valve for improved performance. This head is cast with extra thick port walls and a compact port size, making them ideal for CNC and hand porting. Complete cylinder head includes guide plates, rocker studs and high quality valvetrain for…