Dual Exhaust Header Back Kit - Super Street

The Dual Exhaust Header Back Kit - Super Street (MPN 51525FLT) is a complete header-to-tailpipe exhaust system engineered for small block Chevy 4WD GM fullsize trucks from 1973–74. This header-back configuration replaces the restrictive factory exhaust manifold and piping with a dual 2.25-inch diameter steel system, delivering improved scavenging, horsepower gains, and a classic muscle-car exhaust note. Built for enthusiasts seeking affordable performance without full engine rebuilds, this kit addresses the core bottleneck in vintage truck breathing—exhaust gas evacuation.

The dual-tube steel construction maximizes flow velocity and minimizes backpressure across both cylinders, critical for naturally aspirated small block efficiency. The 2.25-inch diameter represents the ideal balance for carbureted engines in this displacement class—large enough to reduce restriction without sacrificing exhaust velocity that drives cylinder scavenging and fuel atomization. Steel construction offers durability and heat retention, which promotes consistent combustion and reduces underhood temperature swings. The header-back design means you're upgrading from the primaries forward, gaining the largest efficiency improvement per dollar spent compared to bolt-on manifold replacements alone.

This kit is purpose-built for 1973–1974 C10, C20, and K-series trucks with small block Chevy engines (262–400 cu. in. displacement). Installation requires basic mechanical skill: disconnect the original manifold and piping, bolt the headers to the block, and secure the dual tubes and muffler assembly. Weighing 46.13 lbs and dimensioned at 14.2 × 14 × 57 inches, it fits standard frame rails without major modifications. Expect 8–15 horsepower and 10–20 lb-ft torque gains, plus noticeably quicker throttle response and easier cold-start behavior due to improved scavenging efficiency.