GMC Jimmy 1977-1979, 4-2-1 Steel Tri-Y Exhaust Headers with Adapters by Doug Thorley Headers®. Emissions: CARB compliant. Doug's headers are designed to outflow your stock exhaust manifolds by leaps and bounds. Their headers will increase the power of your motor across the widest RPM band possible. That is the beauty of the design, and that is why they are the best street header available.
|Emissions: CARB compliant|
|Header Material: Steel|
- High quality at an affordable price
- Expertly made from premium materials
- Built to match your exact requirements
Doug's Long Tube Headers replace restrictive stock exhaust manifolds with long primary tubes designed to dramatically increase the flow of exhaust gasses, and reduce power robbing back pressure within the exhaust system. Allowing the engine to breathe more freely improves power and efficiency, making Doug's Long Tube Headers one of the most cost-effective modifications you can make to your vehicle.
The Long Tube Header is perfect for any high performance street or strip application. Each header is constructed from thick wall steel, and all come finished with Doug's beautiful ceramic coating for long-lasting performance.
For over 50 years, Doug Thorley Headers has been an innovator in the automotive aftermarket. Driven by a passion for performance and superior quality, they are committed to developing 100% American-made products that will reliably deliver maximum horsepower and torque. Doug Thorley Headers® has been pushing the limits of automotive technology since they first invented the Tri-Y header in 1958, and they do it all on American soil.