Engine - Gaskets/Seals - Competition Head Gasket (4.540 inch)

From GM Performance - This competition designed gasket is for a bore (4.375-4.540 inch) usage on 1965-90 Mark IV Chevrolet big blocks with aluminum heads. It is a preflattened copper wire ring with permatorque/blue stripe coating. The nominal compressed thickness is .041 inch, with compressed volume of 10.9cc. 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 a bore (4.375 to 4.540 inch) usage on 1991 and later Gen V Chevrolet big blocks with aluminum heads. It is a preflattened wire ring. The nominal compressed thickness is .039 inch, with compressed volume of 10.5cc. These are composition design gaskets. Technical Note: This gasket is for Gen V & Gen VI engines only, (1) gasket per package. These gaskets contain stainless core for saltwater marine use.