Header Gasket Set MLS - BBC Round Port 2.250

The Header Gasket Set MLS - BBC Round Port 2.250 is a precision-engineered exhaust manifold gasket pair designed for big block Chevy engines demanding reliable, long-term sealing under sustained heat and pressure. Built for performance enthusiasts, engine rebuilders, and those restoring classic or high-output BBC platforms, this multi-layer steel (MLS) gasket set eliminates exhaust leaks at the critical header-to-cylinder head interface. Proper exhaust sealing is non-negotiable in any serious engine build; a failed gasket compromises horsepower delivery, creates noise, and allows unmetered air into the combustion chamber.

MAHLE ORIGINAL/CLEVITE engineered this gasket set using multi-layer steel construction, a proven material that combines elasticity with thermal stability across the extreme temperature swings of exhaust flow. The 2.250-inch round port design matches the intake and exhaust port geometry of most big block Chevy heads, ensuring proper sealing without material overhang or gaps that lead to leakage. MLS gaskets excel where traditional composite gaskets fail—they tolerate repeated thermal cycling, higher boost pressures, and alcohol or nitrous oxide applications without crush or permanent deformation, making them the standard choice for engine builds targeting reliability above 500 horsepower.

This gasket pair is essential for anyone rebuilding, porting, or refreshing big block Chevy cylinder heads, particularly in high-performance street engines, bracket racing builds, or marine applications where thermal stress is relentless. Installation is straightforward—the gaskets seat against clean, flat manifold and head surfaces and require no sealant when torque specifications are observed. Verify round port head casting compatibility before purchase, as some BBC variants use oval or rectangle port designs that demand different gasket profiles. Proper torque sequence and a quality gasket sealer (optional but recommended for maximum longevity) ensure a sealed system from the first cold start through thousands of miles of service.