Butler Performance Inc. - D-Port Cylinder Heads (Out-of-the-Box) Edelbrock
Edelbrock Aluminum D - Port Cylinder Heads
These heads use the stock Pontiac D-Port exhaust port exits for use with standard D-port aftermarket exhaust systems. Performer Pontiac heads are designed for 1962-79 389, 400, 421, 428 and 455 cid V8 Pontiac engines with a 4.060" or larger bore. Can be used with 350 engine if 1.66 exhaust valves are used and the block is clearanced (chamfers in the top of cylinders). Also, the 62-64 will require 65 and up or aftermarket intake and 67 and up pistons with valve pockets for 14-degree heads. Manufactured with optimized oil return passages for improved flow. Features stock location accessory bolt holes. The casting is manufactured from A356 aluminum and heat treated to T6 spec for superior quality. These heads are available in three dual quench combustion chamber sizes, including 65cc, 72cc, and 87cc. The spark plug has been relocated closer to the exhaust valve for improved performance. Heat crossover is machined for 50-state emissions legal performance.