4.165 MLS Head Gasket .045 - SBC

The Cometic Gaskets 4.165 MLS Head Gasket .045 - SBC is purpose-built for small block Chevrolet engines requiring precision sealing at the cylinder head interface. Whether you're rebuilding a stock 350 or assembling a performance stroker package, this multi-layer steel gasket delivers the bore diameter and compression thickness engineered to maintain reliable sealing across a wide range of boost levels and ambient conditions. Head gaskets are critical components that prevent combustion blowby, coolant intrusion, and oil cross-contamination—making gasket selection as important as block deck preparation.

This MLS (multi-layer steel) gasket construction uses alternating layers of spring steel and elastomer to maintain sealing pressure across thermal cycles and varying loads. The 4.165-inch bore diameter matches late-model small block Chevy heads, while the 0.045-inch compression thickness is calibrated for factory and lightly modified combustion chamber volumes. MLS gaskets excel where traditional composite designs fail—they resist gasket creep, tolerate surface imperfections better than solid copper, and deliver repeatable clamping force retention even after multiple heat cycles. The gasket's perimeter design manages coolant and oil passage isolation without sacrificing durability.

Experienced mechanics and engine builders trust Cometic MLS gaskets for street engines, mild turbocharged applications, and naturally aspirated builds where longevity matters more than extreme peak boost. Installation requires proper head bolt torque sequencing and clean, smooth deck surfaces—any warping, scoring, or previous gasket residue compromises seal integrity. This gasket is sold individually, so confirm your engine configuration and head bolt specification before ordering to ensure correct compression thickness and bore diameter for your specific small block Chevy platform.