SBC IMCA Headers 1-5/8 - 1-3/4

The Schoenfeld SBC IMCA Headers 1-5/8 - 1-3/4 (Model 161-98H) are purpose-built exhaust headers designed specifically for IMCA Modified small block Chevy engines. These headers feature stepped primary tubes ranging from 1-5/8 to 1-3/4 inches, optimized to enhance exhaust scavenging across a wide RPM band typical of dirt track competition. The 3-inch collector consolidates exhaust gases efficiently, reducing backpressure while maintaining velocity. Constructed from mild steel with durable black paint, these headers ship complete with gaskets and hardware, eliminating the need for sourcing additional components before installation.

The stepped primary tube design is a proven approach in short-track racing, allowing smaller diameter sections to increase exhaust velocity during lower RPM acceleration while larger sections manage higher RPM flow without creating excessive restriction. This configuration delivers measurable torque gains throughout the power band—critical for IMCA Modified applications where track conditions demand responsive, predictable power delivery. At 27.28 lbs, these headers are competitively weighted for a complete bolt-on assembly. The included gaskets ensure proper sealing without requiring expensive OEM replacements, and the comprehensive hardware package reduces installation time and complexity on the dyno or in the shop.

IMCA Modified racers and small block Chevy enthusiasts building competition engines rely on Schoenfeld headers for consistent, repeatable exhaust performance. Whether preparing for the 2024 racing season or upgrading an existing power plant, these headers address a specific market: drivers who need proven aftermarket components that comply with IMCA regulations and deliver real dyno-verified gains. The stepped primary tube design and properly sized collector are standard specifications across successful IMCA competitors, making this header choice both technically sound and regulation-compliant.