Cometic 4.250 MLS Head Gasket .040 - AMC 390/401 H76803FM Air Boss 8' Chute Only

Air Boss 8' Chute Only

2007-2017 GMC Sierra 3500 HD

Easy installation with a set screw

ButlerBuilt Aluminum Seat Back Bracket - 3/16"

Cometic 4.250 MLS Head Gasket .040 - AMC 390/401 H76803FM Air Boss 8' Chute OnlyComprised 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