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Cometic GM / Mercury 8.1L 496ci 4.350in Bore .066in MLS-5 LH Head Gasket

SKU: CGSC5765-066

Head Gaskets

CG Head Gaskets...

Cometic GM / Mercury 8.1L 496ci 4.350in Bore .066in MLS-5 LH Head Gasket

SKU: CGSC5765-066

Head Gaskets

CG Head Gaskets...

A$363.13
Special Order. Contact for ETA. This item is out of stock in our warehouse and partner distribution centres. In some cases, this may be due to not having live inventory feeds available for all suppliers. Please contact us before ordering if you need to meet a specific deadline.

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Description

Cylinder Head Gasket

MLS Gaskets are comprised of multiple embossed layers of both AMP (Advanced Multi-Polymer Coating) and uncoated stainless steel

Additional Information

GM L18 Vortec 8100 Gen-VII Big Block V8 .066in. MLS Cylinder Head Gasket; 4.350in. Bore; LHS

Part Type

Engine Cylinder Head Gasket

Product Overview

Comprised of multiple embossed layers of stainless steel with the outer layers utilizing a Viton rubber coating. Compressed operating thickness is 0.098". Cometic MLS (Multi-Layer Steel) Head Gaskets provide maximum sealing performance for todays high output engines and require no sealants. MLS gaskets are ideal for both aluminum heads to aluminum blocks and aluminum heads to cast iron blocks. They can withstand the shearing force created by the two materials. MLS gaskets have increased strength because they are comprised of multiple layers of stainless steel; which also creates the ability to rebound and resist corrosion. The outer layers are embossed and coated on both sides with Viton (a flour elastomer rubber based material that is heat resistant to 250 C/ 482 F). Viton is designed to meet the demands of a variety of harsh sealing environments, load conditions, and surface finishes. The center or shim layer is uncoated stainless steel, which can be varied to accommodate multiple thickness requirements.

Data: v4.2 - Upd: 2026-11-07 21:49:25

Features

  • Coated On Both Sides w/Viton
  • Conforms load distribution across the sealing area
  • Requires less clamp load creating less bore distortion
  • The center or shim layer is an uncoated stainless steel layer which can be varied to accommodate multiple thickness requirements
  • The embossed outer layers of the gaskets meet the demands of a variety of harsh sealing environments, load conditions, and surface finishes

Images are supplied by the manufacturer and may be generic. While all efforts are made to provide accurate pictures, there may be differences in the actual product, such as colour, quantity, version, or included components. Please carefully review the description and specifications for details on inclusions or any variations. Some items may be sold individually or in sets, and images may occasionally depict additional products or quantities not included in your purchase. For assistance or clarification, please contact customer support.

Specifications

Product Details

Description:GM L18 Vortec 8100 Gen-VII Big Block V8 Cylinder Head Gasket
Engine Make/Size:GM/Mercury Marine 8.1L
Part Number:cgsC5765-066
Position:Left
Title:Cometic Gasket Automotive GM L18 Vortec 8100 Gen-VII Big Block V8 .066 in MLS Cylinder Head Gasket, 4.350 in Bore, LHS

Product Downloads

# Document Type Download
1. Installation Instructions

Installation guides, warranty details, and other supporting documents are provided by the supplier. In some cases, these files may originate from regions outside your locale, meaning instructions, warranty procedures, and images may not fully align with your specific vehicle or region (e.g., LHD vs. RHD differences, return policies, etc.). If you need clarification, please contact a StreetFX support agent.

Data: v2 - Desc: v4.2 - Upd: 2026-11-07 18:36:27

Reference Information

Reference Data (Provide these details to our support team)
Brand Name/s Cometic Gasket, Cometic, Cometic Gasket Automotive, Cometic Gasket Marine, Cometic Gasket Powersports, COMETIC GASKETS, Cometic Powersport Gaskets
StreetFX SKU cgsC5765-066
SFX Item ID 4159584
Accounting SKU cgs-C5765-066
Manufacturer SKU C5765-066
Manufacturer UPC 191070076917
Alternative References C5765-066, CGT-C5765-066

.066" MLS-5 LH SIDE HEAD GSKT

Cometic MLS head gaskets are constructed from multiple layers of stainless steel for strength and contain load-controlled embossments that conform load distribution across the sealing area. This creates an exceptional seal by requiring less clamp load—resulting in less bore distortion. The stainless steel outer layers utilize FKM (Viton®) rubber coating, a high-temperature and chemical-resistant polymer. A topcoat of PTFE aids in resistance to fret and increased cold sealing. MLS head gaskets are available for most aftermarket cylinder heads; as with all of Cometic's MLS head gaskets, no sealants or re-torque is required.

Product Attributes
UPC00191070076917
BrandCometic
NotesLeft side. Mercury marine applications.
QuantitySold individually.
Bore (mm)110.490mm
Lock WireNo
Part TypeHead Gaskets
Bore (in.)4.350 in.
Product LineCometic MLS Head Gaskets
Gasket MaterialMulti-layer stainless steel
Compressed Volume (cc)16.074cc
Compressed Thickness (in.)0.066 in.
Manufacturer's Part NumberC5765-066

Compatibility

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