Speedmaster™ head gaskets are proven to handle big power any way you can make it. Speedmaster™ gaskets are designed to maintain contact pressure between the cylinder head and block during the dynamics of engine operation. Speedmaster™ MLS gaskets use a high pressure steel laminate design known for standing up against the extremely high shearing forces that occur between an aluminum head and iron block. It’s internal embossments expand heat to create a better seal when the engine is seeing extremely high combustion pressures and temperatures as is the case with heavy nitrous and turbocharged applications. MLS (Multi Layer Steel) is ideal for both aluminum heads to cast iron blocks and aluminum heads to aluminum blocks. These gaskets offer better torque retention, less distortion, and better sealing than conventional or composite head gaskets in high-horsepower, high cylinder-pressure applications.