Cometic C5817-040 GM Big Block MLS Cylinder Head Gasket Bore - V8 4.320

The Cometic C5817-040 is a premium Multi-Layer Steel (MLS) cylinder head gasket engineered specifically for GM Generation V and VI Big Block V8 engines. This high-performance gasket features a 4.320" bore diameter and a compressed thickness of .040", making it ideal for performance builds and engines requiring precise sealing at the head-to-block interface.

Key Features:

• Multi-Layer Steel (MLS) construction provides superior sealing and durability under extreme cylinder pressures
• 4.320" bore diameter accommodates big bore engine configurations
• .040" compressed thickness allows for precise quench height and compression ratio tuning
• Designed for GM Generation V and VI Big Block V8 engines
• Engineered to handle high-performance and racing applications
• Multiple embossed layers with stainless steel construction resist corrosion and gasket failure

Cometic MLS gaskets are manufactured using multiple layers of stainless steel with proprietary coatings that adapt to surface imperfections and maintain seal integrity through extreme temperature cycling. The MLS design distributes clamping pressure evenly across the gasket surface, reducing the risk of hot spots and blown head gaskets in demanding applications. This gasket is ideal for performance street engines, racing applications, and forced induction setups where reliable cylinder sealing is critical.