Cometic C5712-040 Pontiac MLS Cylinder Head Gasket Bore - 400/428/455 V8 4.300 040

The Cometic C5712-040 is a Multi-Layer Steel (MLS) cylinder head gasket engineered for Pontiac 400, 428, and 455 cubic inch V8 engines. Featuring a 4.300-inch bore and a .040-inch compressed thickness, this gasket is purpose-built to deliver reliable, long-lasting seals in both street and performance applications. Sold individually.

Key Features:

• Multi-Layer Steel (MLS) Construction: Built from 3 to 5 layers of spring stainless steel, providing a stronger base than standard cylinder head gaskets
• Viton-Coated Outer Layers: FKM (Viton®) rubber coating on the stainless steel outer layers delivers a superior seal not achievable with standard steel or copper gaskets, with excellent resistance to heat and chemicals
• PTFE Topcoat: An additional PTFE topcoat aids in fret resistance and improved cold sealing performance
• Load-Controlled Embossments: Conforms clamp load distribution across the entire sealing surface, requiring less overall clamp load and resulting in reduced bore distortion
• No Sealants or Re-Torque Required: Installs dry — the gasket's built-in coatings eliminate the need for additional gasket sealers, which can actually hinder MLS gasket performance
• Suitable for All Engine Configurations: Compatible with aluminum head-to-aluminum block and aluminum head-to-cast iron block combinations; rated for naturally aspirated, boosted, and nitrous-fed engines
• Made in the U.S.A.: Manufactured with materials sourced on American soil; Cometic is an exclusive NASCAR Performance Product

Specifications:

• Part Number: C5712-040
• Material: Multi-Layer Steel (MLS)
• Bore Size: 4.300 in.
• Compressed Thickness: .040 in.
• Number of Layers: 3
• Bore Shape: Valve Pocketed
• Quantity: Sold Individually

Whether you're rebuilding a classic Pontiac GTO, Firebird, or Trans Am powerplant, the Cometic C5712-040 delivers the sealing integrity and durability demanded by today's high-output engine builds.