1-5/8in SBC Flange Square CNC

The 1-5/8in SBC Flange Square CNC header flange is a precision-engineered component designed for small-block Chevy engine builders and performance enthusiasts seeking bolt-on simplicity without compromising exhaust flow. This flanged header fitting serves as the critical interface between your custom header tubes and the engine block, eliminating the need for welding while maintaining structural integrity under sustained high-RPM operation.

Manufactured by Schoenfeld, a trusted name in high-performance exhaust systems, this 1-5/8-inch flange utilizes CNC precision machining to achieve consistent bore sizing and flange flatness that stock cast pieces cannot match. The square flange design provides maximum clamping surface area, distributing bolt load evenly across the mating surface to prevent warping and reduce gasket failure risk. At 1.69 lbs and measuring 18.25 inches in length, this component is designed for durability and reliability.

This flange is ideal for builders fabricating custom headers for small-block Chevy engines (262–400 cubic inch displacement). Its precision-cut geometry ensures proper header tube alignment without forcing or shims, making it suitable for various performance applications. Whether you're building a street machine or a weekend track car, this component is essential for achieving optimal exhaust flow and performance.