4.200 MLS Head Gasket .040 - Pontiac 400-455

The 4.200 MLS Head Gasket .040 for Pontiac 400-455 from COMETIC GASKETS is designed for serious engine builders and mechanics who are restoring or modifying classic Pontiac big-block powerplants. This gasket is ideal for both street and competition use, ensuring reliability and performance in high-compression and forced-induction applications.

Constructed from multi-layer steel (MLS), this head gasket provides superior sealing integrity compared to older composite designs. The .040-inch thickness is specifically calibrated for stock or lightly modified Pontiac 400-455 heads and blocks, ensuring proper combustion chamber volume and piston-to-valve clearance. The MLS construction features multiple stamped steel layers with elastomer coatings, allowing for a durable seal that withstands thermal cycling and pressure spikes.

Owners of Pontiac 400 and 455 engines, especially those upgrading with aluminum heads, higher compression ratios, or nitrous/boost systems, will benefit significantly from the reliability of MLS gaskets. This gasket is engineered to prevent blowby and coolant loss, making it a crucial component for performance builds. Installation follows standard torque-down procedures, ensuring a secure fit for optimal performance.