Headers, Dougs, 1965-68 Bonn/Cat/GP 326/455 1-3/4", Full Length

1965-68 Pontiac Headers, (389-428 D-Port, 1-3/4", Long Tube), by Doug’s Headers®

1.75-inch primary tubes, 3.0-inch collectors and steel long-tube construction.

Doug’s Headers® long-tube headers use 1.75-inch primary tubes and 3.0-inch collectors. The steel tubes meet 3/8-inch head flanges, and the pair includes header gaskets and mounting hardware. Choose metallic ceramic or high-temperature black according to the selected option.

• Construction: steel long-tube headers; 16-gauge tubing and 3/8-inch head flanges. • Primary tube diameter: 1.75 inches; collector diameter: 3.0 inches. • Collector connection: 3-Bolt Flange; exhaust-port shape: D-port. • Finish options: metallic ceramic, high-temperature black. • Supplied as a left/right pair with header gaskets and mounting bolts. • Fitment: 1965–66 Pontiac Bonneville/Catalina/Grand Prix: 389, 421 cu. in; 1967–68 Pontiac Bonneville/Catalina/Grand Prix: 400, 428 cu. in. • D-port cylinder heads only; Drill and tap missing end-bolt holes in factory cylinder heads; Floor shift required.