Cometic C5986-075 GM LS9/LSA MLX Cylinder Head Gasket 4.100" Bore .075" Left Side

The Cometic C5986-075 is a Multi-Layer Steel (MLX) cylinder head gasket engineered specifically for GM LS9 and LSA Gen-4 small block V8 engines. This left-side gasket features a 4.100-inch bore diameter with a compressed thickness of .075 inches, making it ideal for reducing compression ratios in supercharged or high-boost applications.

Key Features:

• 4.100-inch round bore size matches stock LS9/LSA specifications
• .075-inch compressed thickness reduces compression by approximately 0.4 ratio points
• 5-layer MLX construction with integrated stopper layer for enhanced combustion sealing
• Outer layers feature Viton fluoroelastomer coating for superior heat and chemical resistance
• Stainless steel construction provides exceptional rebound characteristics and corrosion resistance
• Compatible with factory LSA/LS3 style head bolts or larger LS9 head bolts
• No re-torque required after installation
• Can be used on LS3, L99, LY6, L96 and similar 6.0L/6.2L applications

Cometic's MLX gaskets combine multiple embossed layers of stainless steel with advanced coating technology to deliver maximum sealing performance in high-output engines. The thicker .075-inch profile makes this gasket particularly useful for boosted applications or when running lower octane fuel, as it helps reduce detonation risk by lowering compression. Ideal for both aluminum-to-aluminum and aluminum-to-cast iron block combinations without requiring sealants.