Cometic C5985-051 GM LS9/LSA MLX Cylinder Head Gasket – 4.100″ Bore, .051″ RHS

The Cometic C5985-051 MLX Cylinder Head Gasket is engineered for GM Gen IV LS9 and LSA supercharged V8 engines, delivering performance-oriented combustion sealing for demanding engine rebuilds and high-cylinder-pressure applications.

Featuring a 4.100-inch gasket bore, .051-inch compressed thickness, and Multi-Layer Steel with an MLX stopper-layer design, this right-hand-side (RHS) cylinder head gasket is intended for compatible GM 6.2L supercharged applications.

Whether you’re rebuilding a Cadillac CTS-V LSA, refreshing a Chevrolet Camaro ZL1, or servicing a Corvette ZR1 LS9, selecting the correct head gasket is essential for maintaining compression, controlling combustion leakage, and preventing coolant and oil contamination.

Key Features and Benefits

• Cometic MLX Technology: Multi-layer steel construction with an engineered stopper layer to concentrate sealing load around the combustion chambers.

• 4.100-Inch Gasket Bore: Sized for compatible GM LS9 and LSA engine configurations.

• .051-Inch Compressed Thickness: Provides a defined gasket thickness for accurate engine assembly.

• Right-Hand-Side Configuration: Designed for the specified RHS cylinder bank.

• Forced-Induction Applications: Engineered for demanding supercharged engine environments.

• Precision Sealing: Helps separate combustion pressure, coolant passages, and engine oil.

• Performance Rebuild Compatibility: Suitable for properly prepared stock and modified LS9/LSA engine assemblies.

Technical Specifications

Why Choose Cometic MLX for Your Supercharged LS Engine?

The GM LS9 and LSA engines are designed to produce substantial horsepower and torque through factory supercharging. This creates demanding operating conditions for cylinder head gaskets, particularly when pulley changes, increased boost, or engine tuning raise cylinder pressure.

Cometic’s MLX construction incorporates a stopper-layer design that helps concentrate clamping force around the cylinder bores.

This approach is intended to improve combustion sealing in properly assembled high-performance engines.

Unlike a conventional composite head gasket, MLX construction uses engineered steel layers to accommodate thermal cycling and maintain sealing pressure.

Important: Even a premium MLX gasket cannot compensate for improper cylinder head clamping, excessive deck distortion, detonation, or incorrect engine tuning.