What is the purpose of the Viton coating on the gasket?

The Viton coating on the embossed outer layers helps create a more effective seal against the cylinder head and block surfaces. It also adds resistance to engine oils and other fluids, contributing to a longer-lasting and leak-free seal.

Does this gasket come with any installation hardware?

This product is for the head gasket only. It does not include head bolts or other installation hardware. It is recommended to use new head bolts and follow the manufacturer's torque specifications and tightening sequence during installation.

What does '18/23 Degree Head' refer to?

This refers to the angle of the cylinder head combustion chamber where it meets the piston. This gasket is specifically designed to seal engines that use cylinder heads with this particular 18/23 degree angle.

Specifications

Brand: Cometic Gasket
Part #: C15412-043
UPC: 191070438609

Cometic GM SB 18/23 Deg 4.200in Bore 0.043in Copper Head Gasket (No Steam Holes)

Name: Cometic GM SB 18/23 Deg 4.200in Bore 0.043in Copper Head Gasket (No Steam Holes)
Brand: Cometic Gasket
SKU: cometic-gasket-cometic-gm-sb-18-23-deg-4-200in-bore-0-043in-copper-head-gasket-n-t14-200550
Price: 126.18 USD
Availability: BackOrder

$126.18

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Cometic GM SB 18/23 Deg 4.200in Bore 0.043in Copper Head Gasket (No Steam Holes). For rebuilding GM Gen-1 Small Block V8 engines.

Key Features

Fits a wide range of GM vehicles with 18/23 degree cylinder heads and a 4.200 inch bore.
Copper construction offers excellent conformability and heat resistance.
Embossed outer layers are coated with Viton for improved sealing and fluid resistance.
0.043 inch thickness is ideal for many performance engine builds.
Features a valve pocketed bore design for a precise fit around the valve area.
No steam holes for specific sealing requirements.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Will it fit your car?

About this part

Product Details

If you're rebuilding the top end of a GM Gen-1 Small Block V8, this Cometic copper head gasket is a solid choice. It's designed for engines with an 18/23 degree cylinder head angle and a 4.200 inch bore, with a thickness of 0.043 inches. This gasket doesn't have steam holes, which is common for certain performance applications where precise sealing is critical.

The gasket itself is made of copper, a material known for its ability to conform to sealing surfaces and handle high temperatures. Cometic applies an embossed outer layer coated with Viton, a high-performance fluoroelastomer. This coating helps create a better seal and adds resistance to oil and other fluids, ensuring a more durable and leak-free assembly. The valve pocketed bore design means it's specifically shaped around the valve area for a precise fit.

This gasket fits a wide range of GM vehicles from the early 80s, including popular models like the Chevrolet C10, Camaro, and GMC C1500. Make sure to check the full fitment list to confirm it's the right part for your specific build.