Headers

All PMI OHC-6 headers are designed specifically for the Pontiac OHC-6 engine and are NOT “adapted” from other motors. Featuring tuned lengths in both the primary and secondary runs, all PMI headers are manufactured from heavy-wall 16-gauge steel tube and 3/8” thick cold-rolled steel flanges.

Merge collectors are featured on all header designs.

All PMI OHC-6 headers will fit 1966-1967 “A” body chassis, all 1967 to 1969 “F” body Chassis and all 1968-1969 “A” body chassis with Power Steering, Power Brakes, AIR pump, air conditioning, manual transmission with floor shift, manual transmission with column shift, automatic transmission with floor shift, automatic transmission with column shift and all 1969 “A” and “F” body cars fitted with back-drive linkage. 1967 "F" body may require a throttle adapter bracket. (Order the throttle adapter from Primatech if you have a 1967 Firebird.)  O₂ sensor bungs available; please specify when ordering.  Natural, ceramic and 1400°F powder coat finishes are available.

PMI headers feature mounting flange options never offered before on in-line headers: Dual and Single flange designs are available for virtually all PMI headers.

Dual Flange: PMI’s dual flange system separates the front and back half of the 3/8” thick header mounting flanges into separate flange plates for each cylinder set. This will allow you to run any of the factory Sprint 4 barrel intake manifolds, or other available aluminum intake manifolds without modifications.  (An adapter kit is in the works from Primatech to combine the headers with 1–Barrel intake manifolds.)

Single Flange: PMI’s unique single flange header mounting plate bolts to the head as a single piece. The intake manifold can be removed without disturbing the manifold-to-head seal. This set up will work with all PMI intake manifolds or any factory intake manifold using the supplied gasket and mounting kit.   Kit includes all of the gaskets, studs bolts, nuts and washers.  Not recommended for aftermarket intake manifolds.

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PMI’s OHC-6 header is a balanced-flow header featuring tuned length primaries, merge collectors and dyno-tuned secondary collector length. This is a true 6-into-2-into-1 header, available with standard Dual Flange or PMI’s unique Single flange mounting systems. 16 gauge tubing is standard; available in 1-5/8” and 1-3/4” primary tube diameters. (2.0” tubing is also available for forced induction applications. Contact PMI for pricing and delivery.)

COMING SOON! Stainless Steel OHC-6 Headers!

Tri-Y (6-3-1) -- under development

PMI’s “Tri-Y” OHC-6 header also features either Dual Flange or Single Flange mounting. This header design brings the opposite-firing cylinders together to increase scavenging at low RPM, increasing torque and providing a broad, flat torque curve up to 5,500 RPM. Merge collectors are used throughout. This header is available in 1-5/8” and 1-3/4” diameter primary runs with 2.0” and 2-1/4” secondary runs. Final run is 2-1/4” or 2-1/2”.

True Dual (2x 3-into-1) -- under development

Our True Dual header design features two individual long tube tuned headers. Extensive testing has shown performance gains by combining both sides of the header into a single secondary collector, but PMI’s True Dual system can be used for dual exhaust that delivers excellent performance and that unique inline six sound. Chassis fit is exceptional. This header is available with dual flange only.

Single Turbo -- under development

When normally aspirated motors don’t do enough for you, turn to PMI’s forced induction experts. Our single T-3/4 set up gives you all the boost of a turbo charger in a custom built set-up. Our supreme standards of design and fit guarantee a perfect fit and incredible performance. Contact PMI for pricing and delivery. Complete packages including camshaft intake manifold, EFI system, turbocharger and exhaust are available for eye-popping bolt-on performance gains. As with all higher-performance exhaust products from PMI, the single turbo header is available in 1-3/4” and 2.0” primary tubes and single and dual flange mounting.

Twin Turbo -- under development

If one turbo is good, two must be better. The PMI twin T-3/4 system is nothing short of spectacular. This induction and exhaust system brings the pioneering OHC-6 into the 21st century with performance unheard of a generation ago. Complete top end packages are available in all stages to meet any performance demands. Contact us for information, pricing and technical assistance