Cometic H3290SP4043C MLS Cylinder Head Gasket 4.043" Bore .040" Thickness

The Cometic H3290SP4043C is a Multi-Layer Steel (MLS) cylinder head gasket featuring a 4.043" bore diameter and .040" compressed thickness, engineered for high-performance and performance-rebuilt engines demanding superior sealing integrity.

Key Features:

• Multi-Layer Steel (MLS) Construction: Comprised of multiple embossed stainless steel layers — outer layers coated with a proprietary Viton (FKM) fluoroelastomer for chemical and heat resistance up to 482°F (250°C)
• 4.043" Bore Diameter: Precision-punched bore sized for proper combustion seal clearance over the cylinder bore
• .040" Compressed Thickness: A popular stock-replacement and mild performance thickness that maintains correct compression ratio and quench distance
• Load-Controlled Embossments: Distributes clamping load evenly across the sealing surface, reducing bore distortion and requiring less torque to achieve a reliable seal
• No Re-Torque Required: MLS design holds torque retention without the need for a re-torque after initial break-in
• Dry Installation: Pre-coated with Viton sealant — no additional gasket sealer or sealant compounds should be applied
• Compatible with Aluminum-to-Cast Iron and Aluminum-to-Aluminum Applications: The MLS construction withstands differential thermal expansion between dissimilar metals

Cometic's MLS head gaskets are manufactured to exacting tolerances and are ideal for naturally aspirated, turbocharged, supercharged, and nitrous-assisted engine builds. For best results, Cometic recommends a surface finish of 50–80 Ra on both the block deck and cylinder head mating surfaces.