4.170 MLX Head Gasket .040 SBF 289-351W

The Cometic 4.170 MLX Head Gasket .040 SBF 289-351W is a precision-engineered cylinder head gasket designed for serious small-block Ford engine builders and enthusiasts. This gasket bridges the critical seal between your cylinder head and engine block, preventing coolant and combustion gas leakage while maintaining compression integrity under high heat and pressure. If you're rebuilding a 289 or 351W small-block Ford—whether for street performance, racing, or restoration—selecting the right head gasket is non-negotiable for engine longevity and reliability.

Cometic's MLX gasket line represents the evolution of multi-layer steel (MLS) technology, combining elastomer-coated steel layers to distribute clamping load evenly across the gasket surface. The .040-inch compressed thickness accommodates your engine's deck height and head surface finish while maintaining proper bore clearance—critical when running higher compression ratios or modified cylinder heads. The 4.170-inch bore diameter is sized specifically for 289 and 351W applications, ensuring the gasket seals the combustion chamber without compromising coolant or oil passage accessibility.

This gasket excels under both naturally aspirated and boosted conditions, resisting extrusion and micro-movement that plague inferior rubber-only designs. Bolt-torque builders and engine shops rely on Cometic MLX gaskets for 289-351W rebuilds because they eliminate the guesswork of head gasket failure after dyno testing or track use. With compatibility for both iron and aluminum cylinder heads, this gasket is a reliable choice for any serious engine builder.