Engine - Gaskets/Seals - Competition Head Gasket (4.370 inch)

From GM Performance - This competition designed gasket is for standard bore (4.250 to 4.370 inch) usage on 1965-90 Mark IV Chevrolet big block with aluminum heads. It is a preflattened copper wire ring with permatorque/blue strip coating. The nominal compressed thickness is .039 inch, with compressed volume of 9.7 cc. These are composition design gaskets. Technical Note: This gasket is for Mark IV engines only, (1) gasket per package.

From GM Performance - This competition designed gasket is for bore (4.250 to 4.370 inch) usage on 1991 and later Gen V and VI Chevrolet big blocks with aluminum heads. It is a preflattened wire ring. The nominal compressed thickness is .039 inch with compressed volume of 9.7cc. These are composition design gaskets. Technical Note: This gasket is for Gen V and Gen VI engines only, (1) per package. These gaskets contain stainless core for saltwater marine use.