Tri-Y Exhaust Header with 1.625-Inch Primary Tubing and

The Doug's D690YS header is a performance-grade exhaust component engineered with a pioneering TRI-Y design. This unique configuration of paired, short-end primary tubes is intended to boost mid-range torque without compromising top-end power, making it suitable for daily drivers and trucks aiming for improved performance from idle up to 4500 RPM while maintaining fuel efficiency. The construction features CNC mandrel-bent steel tubes with a 16-gauge wall thickness for precise fitment and optimal flow, complemented by 3/8” thick machined flanges to prevent warping. The header boasts a durable Metallic Ceramic Coating, which acts as a thermal barrier to lower under-hood temperatures and protect against thermal fatigue. This coating is then polished to a high-luster aluminum finish, resulting in a surface that is 60% more corrosion resistant than unpolished alternatives. Specific fitment is for 1964-1970 Ford Mustang and Mercury Cougar models equipped with V8 engines (260, 289, or 302 cubic inches) and manual transmissions. Installation may require the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar. For vehicles with power steering, bracket PN H7609 is needed. Vehicles equipped with Air Injection heads will require grinding of the header flange for fitment. Additionally, use the recommended C5ZZ16A052E "export brace" if the shock mount center-to-center dimension is less than 33 3/4 inches. This header will not fit GT40 "P" heads. Gaskets and mounting hardware are included. This product is certified by the manufacturer as a non-emissions related part per CARB and EPA regulations, making it legal for sale and use in all 50 states.