Cometic C5434-140 MLS Cylinder Head Gasket Chevy Big Block Bore - for V8 4.630

The Cometic C5434-140 is a premium multi-layer steel (MLS) cylinder head gasket engineered specifically for Chevrolet Mark-IV and GM Gen-V/VI Big Block V8 engines. This high-performance gasket features a 4.630-inch bore diameter and .140-inch compressed thickness, providing exceptional sealing performance for both street and racing applications.

Key Features:

• Multi-layer steel construction for superior clamping and sealing under extreme cylinder pressures
• 4.630-inch bore diameter accommodates a wide range of big block builds
• .140-inch (3.6mm) compressed thickness allows for precise compression ratio tuning
• Undersized water ports designed for aftermarket heads, allowing custom port matching and coolant flow optimization
• Compatible with Chevrolet Mark-IV and GM Gen-V/VI Big Block V8 platforms
• Stopper layer technology prevents gasket failure from over-compression

Cometic gaskets are manufactured using advanced materials and embossing techniques that ensure consistent clamping pressure across the entire sealing surface. The undersized water ports give engine builders the flexibility to match coolant passages precisely to their specific aftermarket cylinder heads, maximizing cooling efficiency and preventing potential leak paths.