Header Stock Car IMCA

The Header Stock Car IMCA is purpose-built exhaust manifold engineered for IMCA-sanctioned stock car racing and competition vehicles. Designed by SCHOENFELD, a leader in racing exhaust systems, this header delivers the scavenging efficiency and durability that weekend racers and serious competitors demand. Whether you're campaigning in IMCA oval track events or building a high-performance street-legal modified engine, the Header Stock Car IMCA provides the flow characteristics necessary for maximizing horsepower and torque across the RPM band while meeting class regulations.

Constructed from heavy-duty steel and weighing 23.2 lbs, this header utilizes tuned runner lengths and cross-sectional geometry optimized for pulse scavenging—a critical principle in racing exhaust design that harnesses exhaust gas velocity to extract spent gases more completely from the cylinder head. The manifold's primary tubes are sized and arranged to match stock displacement engines while accommodating forced induction applications. Proper header installation improves cylinder evacuation, reduces pumping losses, and allows the intake stroke to begin with fresher charge mixture, directly increasing volumetric efficiency. The compact 20 x 9 x 23-inch envelope fits within tight engine bay constraints without compromising tube routing or collector optimization.

IMCA stock car racers will find this header compliant with most sanctioning body regulations while delivering measurable power gains over factory cast-iron manifolds. Installation requires basic automotive tools and exhaust system knowledge—proper gasket sealing and bolt torque sequence are essential to prevent exhaust leaks that degrade performance and cause heat management issues. Mechanics and engine builders appreciate SCHOENFELD's attention to detail in flange accuracy and runner finish, which reduces installation time and ensures reliable service throughout a racing season. Compatible with standard 1.5- or 1.625-inch flange bolt patterns found on most small-block and mid-sized displacement racing engines.