4.180 MLS Head Gasket .040 - SBM

The Cometic Gaskets 4.180 MLS Head Gasket .040 for Small Block Mopar is a multi-layer steel cylinder head gasket engineered for precise sealing in high-performance small block Mopar engines. This 0.040-inch compression thickness gasket is designed for builders and engine rebuilders who demand reliable combustion chamber sealing across repeated thermal cycles and elevated boost conditions common in street performance and racing applications.

The multi-layer steel (MLS) construction provides superior sealing capability compared to traditional composite gaskets, with embedded elastomer layers that compress uniformly to maintain consistent compression height throughout the engine's operating range. The 4.180-inch bore diameter matches the cylinder opening of small block Mopar heads, ensuring proper gasket coverage and preventing combustion leakage at the cylinder wall. The 0.040-inch thickness is a critical specification—it directly affects compression ratio, so precise matching with your engine's deck height and head gasket pocket depth is essential for achieving target piston-to-valve clearance and compression specifications.

This gasket is intended for small block Mopar engine builders working on 318, 340, and 360 cubic inch platforms where OEM or performance head gasket replacement is required. Whether you're performing a stock rebuild, upgrading to modern aluminum cylinder heads, or building a performance engine for street or strip duty, proper head gasket selection is non-negotiable for reliability. Cometic's reputation in the performance gasket market makes this product a trusted choice among engine machine shops, restoration specialists, and serious DIY builders.