Cometic MLS Exhaust Gasket Engineered Specifically for GM LSX Cylinder Heads
The SS-755818 is a Cometic multi layer steel exhaust gasket designed for GM LSX cylinder heads, delivering professional grade sealing performance at the header flange to cylinder head interface. Cometic is a recognized leader in high performance gasket manufacturing, and their MLS technology is used in professional motorsports and high horsepower street applications where a standard gasket would fail under the combination of extreme temperatures, high clamping loads, and repeated thermal cycling. This gasket brings this level of gasket engineering to LSX powered builds where performance headers are installed.
The LSX cylinder head is a high flow aftermarket racing head that differs from the standard LS production heads in port dimensions and face configuration, and the SS-755818 is sized and stamped specifically for the LSX head geometry rather than being a generic LS part. Using the correct Cometic MLS gasket for the LSX application ensures the exhaust port opening matches, the bolt holes register correctly, and the multi layer construction provides the sealing integrity these demanding performance applications require. If you are running LSX heads with Kooks headers, this is the gasket to use.
Key Features
- Cometic brand multi layer steel gasket for premium sealing performance
- Engineered specifically for GM LSX cylinder head exhaust port geometry
- Multi layer steel construction maintains clamping load across heat cycles
- Precision stamped for correct port and bolt hole alignment
- Suitable for high horsepower and forced induction LSX builds
- Compatible with Kooks header applications on LSX cylinder heads
What’s Included
- this gasket Cometic MLS exhaust gasket set for GM LSX cylinder heads (quantity as required for application)
Specifications
| Specification | Detail |
|---|---|
| Part Number (MPN) | SS-755818 |
| UPC | Contact us for UPC |
| Gasket Type | Cometic Multi Layer Steel (MLS) |
| Application | GM LSX Cylinder Heads |
| Use With | Kooks Header Applications on LSX Heads |
Frequently Asked Questions
What cylinder heads does this gasket fit?
This gasket is designed for GM LSX cylinder heads, which are aftermarket racing heads in the GM LS family. It is not necessarily interchangeable with standard LS production head gaskets due to differences in port size and geometry.
What is Cometic MLS technology?
Cometic is a high performance gasket manufacturer supplying professional racing teams across NASCAR, NHRA, and other major series. Their MLS gaskets use precision stamped steel layers with a proprietary coating to provide consistent sealing under extreme temperature and pressure conditions that exceed the capabilities of conventional stamped gaskets.
Is this gasket the same as a standard LS exhaust gasket?
No. This gasket is specifically dimensioned for LSX cylinder heads. LSX heads have different port dimensions than standard LS production heads. Using a standard LS gasket on an LSX head may result in port mismatch or bolt hole misalignment.
Can I reuse this gasket after header removal?
No. MLS gaskets should be replaced each time the header is removed. The layers compress permanently during initial installation and cannot be relied upon to seal correctly after reinstallation.
Do I need gasket sealant with this gasket?
No. Cometic MLS gaskets are designed to seal without additional sealant. Using sealant on an MLS gasket is not recommended and may interfere with proper sealing.
What torque specification should I use?
Use the torque specification provided in your Kooks header installation instructions. Cometic MLS gaskets require adequate clamping force for proper activation of the multi layer sealing system.
Is this gasket suitable for forced induction LSX builds?
Yes. Cometic MLS gaskets are routinely used in supercharged and turbocharged racing applications where exhaust temperatures and pressures are elevated significantly beyond naturally aspirated levels.
Will this gasket work with aftermarket LSX heads from other manufacturers?
This gasket is designed for GM LSX head dimensions. Aftermarket heads marketed as LSX compatible may or may not match these exact dimensions. Verify port and bolt hole dimensions before ordering.
How many gaskets are included?
Contact us to confirm the exact quantity for your specific installation. A complete V8 application requires gaskets for all eight exhaust ports.
Where can I find the correct torque spec for my LSX header installation?
The Kooks header installation instructions included with your headers will specify the correct torque value. This is the most reliable reference for your specific application.
Installation Instructions
- Clean the LSX cylinder head exhaust port sealing surface thoroughly, removing all old gasket material.
- Do not apply sealer to this gasket or the cylinder head surface.
- Confirm this gasket port opening aligns with the LSX head exhaust ports and that all bolt holes register correctly.
- Position the header flange over the gaskets and thread all bolts by hand before applying torque.
- Torque all bolts in a crossing pattern to the specification in the Kooks header installation instructions.
- Re torque after the first heat cycle to ensure complete gasket seating.
Prop 65 Warning
WARNING: This product can expose you to chemicals including Chromium and Nickel, which are known to the State of California to cause cancer, birth defects or reproductive harm. For more information go to www.P65Warnings.ca.gov.





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