The exhaust manifolds found in the 1965-1973 Chevy and GMC Big Block engine were designed to combine the exhaust gasses from each of the cylinders quickly with a manifold that was cost effective to produce. Our 4-1 Mid-Length off-road headers are designed to allow the exhaust gasses to flow more freely from each 4 cylinder
The exhaust manifolds found in the 1965-1973 Chevy and GMC Big Block engine were designed to combine the exhaust gasses from each of the cylinders quickly with a manifold that was cost effective to produce. Our 4-1 Mid-Length off-road headers are designed to allow the exhaust gasses to flow more freely from each 4 cylinder bank and combine in a more efficient manner. Tubing has been optimized for the 6. 5L (396ci), 6. 6L(402ci) 7. 0L(427ci) and 7. 4L(454ci) engines. This creates a reduction in cylinder backpressure and improved exhaust gas velocity. These improvements free up lost horsepower and torque. An added benefit is a more performance oriented exhaust sound.
