Remflex 3003 Square Port Exhaust Header Gasket – 2-Pack for Ford V8 Windsor 302/351 (81-97)

Overview

Meet the Remflex 3003 Square Port Exhaust Header Gasket, designed for Ford V8 Windsor engines. This gasket lives at the interface where square-port headers meet the cylinder head, a spot that endures repeated heating and cooling cycles. Crafted from 100% flexible graphite, it aims to maintain a seal even as metal parts expand and contract during operation, helping to minimize leaks without relying on traditional rubber components.

Compatibility and fit

The gasket set is built around the stock 1-1/8 inch width by 1-1/2 inch height square-port pattern. It fits Ford V8 Windsor powerplants in the 302 (1981–1995) and 351 (1969–1997) families, with the 2-per-set configuration giving you enough material for a complete header pair installation.

• 1-1/8" width x 1-1/2" height square port
• Stock square port; Ford V8 Windsor families
• 2 gaskets per set
• Fits 302 ('81-'95) and 351 Windsor ('69-'97)

Material, design, and sealing action

With a standard thickness of 1/8 inch, these gaskets are designed to crush about 50%, filling pits and minor surface irregularities up to 1/16 inch. The 100% flexible graphite formulation contains no rubber binders or composite materials, reducing the risk of shrinking or hardening over time. This composition helps the gasket accommodate the contraction and expansion of dissimilar metals, such as aluminum heads paired with steel headers or manifolds, while aiming to maintain a consistent seal across temperature swings.

• 1/8" thick; crushes ~50% to fill gaps
• 100% flexible graphite; no rubber binders
• Seals dissimilar metals through thermal cycles
• Resists shrinking and hardening with heat

Practical use and expectations

In real-world setups, this gasket is intended to address common leaks at square-port interfaces. Depending on your engine configuration, you may notice fewer leaks at the flange, a more stable seal across heat cycles, and potentially less re-tightening required after a break-in period. The graphite-based design supports creep under pressure, helping maintain a seal as parts move with temperature changes.

• Potential reduction in flange leaks
• Improved seal stability across heat cycles
• May reduce the need for frequent re-tightening

What’s included and installation notes

This 2-pack is sized for stock square-port configurations and is compatible with standard header or manifold surfaces. For best results, ensure mating surfaces are clean and lightly prepared to promote seating. Use proper torque on mounting bolts and follow standard header installation practices. These gaskets are designed to complement proper flange preparation, not replace it.

• Two gaskets included
• Clean mating surfaces before install
• Follow standard torque procedures
• Works best with proper flange prep