Cometic C5399-040 Chevrolet Small Block MLS Cylinder Head Gasket Bore - Gen-1 V8 040 4.030

The Cometic C5399-040 is a Multi-Layer Steel (MLS) cylinder head gasket engineered specifically for Chevrolet Generation 1 small block V8 engines. This performance gasket features a .040" compressed thickness and is designed for a 4.030" bore diameter, making it ideal for custom engine builds and performance applications.

Key Features:

• Multi-Layer Steel (MLS) construction provides superior sealing and durability under high compression and temperature conditions
• .040" compressed gasket thickness allows for precise deck height and compression ratio tuning
• 4.030" bore diameter accommodates standard and slightly overbored Gen-1 small block engines
• Undersized water ports enable customization for aftermarket cylinder heads with non-standard water jacket configurations
• Compatible with aftermarket performance cylinder heads requiring custom port matching
• Embossed stainless steel layers with elastomeric coating ensure consistent clamping pressure and seal integrity

This gasket is specifically designed for engine builders and performance enthusiasts who are using aftermarket cylinder heads on Chevrolet 262-400 cubic inch small block V8 engines (including 265, 283, 302, 305, 327, 350, and 400). The undersized water ports provide flexibility for custom porting work and ensure proper sealing with heads that have modified or relocated coolant passages.