Doug's Headers D590-SS Long Tube 304 Stainless Steel Headers for Pontiac 326-455 V8

The Doug's Headers D590-SS is a long tube, one-piece exhaust header set crafted from 304 stainless steel, purpose-built for 1967–1972 Pontiac GTO, LeMans, and Tempest models equipped with 326–455 cubic inch V8 engines. Designed for maximum exhaust flow and durability, these headers deliver measurable gains in horsepower and torque across the full RPM range.

Key Features:

• 304 stainless steel construction — resists rust and corrosion for long-term durability
• 1-3/4 in. primary tube diameter — optimized sizing for Pontiac 326–455 V8 displacement
• 3 in. collector port diameter for maximum exhaust flow and reduced backpressure
• D-Port flange design — matches factory Pontiac D-shaped exhaust ports
• 3/8 in. thick machined flanges — precision machined to prevent warping under heat cycles
• CNC mandrel-bent primary tubes — maintain consistent inner diameter for improved exhaust velocity and accurate fit
• 16-gauge tubing — durable wall thickness for performance and longevity
• Natural stainless finish — ready for custom finishing or left as-is for a classic look
• Complete hardware kit included — comes with all necessary mounting hardware, collector reducers or connector pipes, premium exhaust gaskets, and detailed installation instructions

Doug's Headers has been a trusted name in performance exhaust since 1958, hand-building mandrel-bent headers for American muscle cars. The D590-SS is developed and fitment-verified on the actual vehicles it's designed for, ensuring a precise, hassle-free installation. Backed by a one-year warranty against defects in materials and workmanship for the original purchaser.

Note: Header applications are based on original engine and cylinder head port centerlines. Raised port or aftermarket cylinder heads may cause installation issues — verify compatibility before installing.