4.380 MLS Head Gasket .040 - BBM

The 4.380 MLS Head Gasket .040 - BBM from Cometic Gaskets is designed for serious big-block engine builders and performance mechanics who require reliability under extreme combustion pressures. This multi-layer steel head gasket effectively seals the critical interface between the cylinder head and engine block, preventing coolant leaks, oil seepage, and combustion gas bypass that can compromise engine performance and longevity.

Constructed from multi-layer steel (MLS), this gasket provides superior sealing compared to conventional composite gaskets. The .040-inch thickness is calibrated for specific bore and deck configurations, ensuring proper head gasket crush and optimal combustion chamber compression ratios. The 4.380-inch bore diameter indicates this gasket is specifically designed for big-block engines with that bore size.

This gasket excels in high-RPM, high-boost, and nitrous applications due to its steel layers, which resist extrusion and maintain sealing integrity under dynamic pressure spikes. Engine builders and performance enthusiasts will find this gasket essential for achieving safe and efficient operation in their high-performance builds.