4.165 MLS Head Gasket .027 - SBC

The 4.165 MLS Head Gasket .027 - SBC from Cometic Gaskets is engineered for small-block Chevrolet engines requiring precision sealing at the cylinder head interface. This component addresses the critical need for reliable combustion chamber sealing in both street and performance applications, where even microscopic leakage can compromise compression, reduce power delivery, and introduce coolant into the oil. Built for builders and engine shops who demand gasket integrity under sustained boost, high RPM, and thermal cycling, this gasket delivers the repeatability and durability that separates a long-lived build from a costly rebuild.

Cometic's multi-layer steel (MLS) construction uses precisely stamped stainless steel layers bonded with elastomer to distribute clamping load evenly across the head deck, eliminating soft-spot failures common in single-layer gaskets. The .027-inch compressed thickness is calibrated for small-block Chevrolet head geometry, ensuring correct combustion chamber volume and piston-to-valve clearance without requiring costly block or head deck work. MLS gaskets excel under thermal shock and vibration because the layered design allows micro-movement between layers, preventing the stress concentration that cracks conventional gaskets. This technology is the industry standard for turbocharged, supercharged, and naturally aspirated high-compression builds where traditional cork or composite gaskets cannot maintain a seal cycle after cycle.

This gasket is purpose-built for the small-block Chevrolet platform—including 262, 283, 305, 327, 350, and 400 cubic-inch variants—making it essential for restorations, engine swaps, and performance upgrades where OEM gaskets have failed or maximum sealing reliability is required. Installation requires careful head deck cleaning to bare metal, proper torque sequence, and adherence to manufacturer specifications for clamp load; Cometic recommends using hardened fasteners and following a three-step torque sequence to achieve uniform gasket compression. Whether you're rebuilding a vintage muscle car, preparing a drag-strip competitor, or assembling a street engine destined for years of dependable service, this MLS head gasket provides the engineering margin necessary for peace of mind and long-term reliability.