Cometic GM Gen II/ Mark IV BB 4.630in Bore .040in MLS (396 / 402 / 427 / 454) Head Gasket 400008 4L TB 'Silicone Reducer 4

4L TB 'Silicone Reducer 4

Installation Time - 2 Hours Or Less

Extang -P/N: 94638 - Trifecta Signature 2

Speaker-In (8 Ch + additional 4 Ch with optional F4IN card): 2

Cometic GM Gen II/ Mark IV BB 4.630in Bore .040in MLS (396 / 402 / 427 / 454) Head Gasket 400008 4L TB 'Silicone Reducer 4Comprised of multiple embossed layers of stainless steel with the outer layers utilizing a Viton rubber coating. Compressed operating thickness is 0. 040". Cometic MLS (Multi Layer Steel) Head Gaskets provide maximum sealing performance for todays high output engines and require no sealants. MLS gaskets are ideal for both aluminum heads to aluminum blocks and aluminum heads to cast iron blocks. They can withstand the shearing force created by the two