A thick base gasket does two jobs at once: it seals the carburetor to the manifold and it puts a quarter inch of insulating material between the two, which slows heat soak into the fuel bowls on a hot day. The four hole pattern keeps the runners separated rather than opening the plenum up.

Mr. Gasket 758 Performance Carburetor Base Gasket Features:

• Fits Holley 4-barrel squarebore carburetors with a 1-5/8 in. bore up to 600 cfm.
• 4-hole design.
• Made from durable 1/4 in. thick cellulose and nitrile composite gasket material.
• Precision die cut for an excellent seal and fit.
• Can be trimmed if necessary.