• Cut from .040-inch thick dead soft copper sheet material
• Reusable copper header gaskets provide ultimate sealing, even on irregular surfaces
• Raised ridge port seal enhances sealing and prevents blow outs
• Natural high temperature use that will not burn or deteriorate like paper gaskets
• Best gasket option for high performance use, turbo setups, and more
• Square exhaust ports feature 1.38-inch x 1.38-inch inside dimensions
• Exhaust port opening can be enlarged up to 1.50-inch x 1.50-inch
• Copper gaskets seal most any manifold or header to your square port SBC heads
• Seals imperfect header and cylinder head surfaces that paper gaskets can’t
• Includes 12 zinc plated heat treated 3/8-16 x 1" header bolts

Stop Wasting Money on Cheap Paper Exhaust Gaskets

When buying headers for your ride many of the brands you’ll find provide gaskets and header bolts in the box for a complete installation solution. While this is admirable of the manufacturer, often the included header gaskets (and even the bolts at times) are made from subpar materials to keep product costs down while providing this “everything you need in one box” purchase mentality. The truth of the matter is that these paper/fiber header gaskets may help get your headers installed but they certainly will not seal very well or last exceptionally long. The main issue is sealing. Both the headers and even the cylinder head port surface can have irregularities that cause the gasket to not seal and to be easily blown out. Add to that issue that paper based gaskets often can’t handle the intense exhaust heat in some applications and will burn/turn hard, causing leaks as well. The answer? High quality ThermoTight dead soft copper gaskets that form over minor imperfections for a better seal that are also reusable, saving you money overall.

Dead Soft Copper for Superior Sealing and Reusability

Paper and other fiber-based gaskets are not the best materials to use for sealing exhaust systems. Sure, you can slather on a bunch of silicone or other gasket maker to help but that just makes a mess of your engine and headers. What about soaking those paper gaskets in water to expand them for a better seal? Sure, it’s an old hot rodder trick that might help, once! Or the gaskets may completely fall apart on you. No, the best sealing is offered via materials like dead soft copper. Stamped from .040-inch thick dead soft copper gasket material, this malleable material easily conforms to header exhaust port weld beads and other tough sealing issues like gouges or even minor corrosion pitting on the exhaust face of your cylinder heads or headers/manifolds.

The dead soft copper header gaskets maintain their softness and have no annealing properties so the copper exhaust gaskets can be formed repeatedly to maintain the best seal use after use. This makes the ThermoTight copper exhaust gaskets perfect for engines that see a lot of header or manifold removal like race cars, engines that see a lot of tear down like turbo setups, or enthusiasts that like to change headers with under car exhaust to zoomies or outside the frame lake pipe setups on their SBC powered rides for an event or cruise. The embossed sealing ridge on the SBC copper header gaskets (which always faces the header flange) helps sealing even further by adding additional conformity to the material, while helping to maintain the gaskets reusability and durability.

Overcome High Heat Exhaust Gasket Failures, Blowouts, Leaks, and More

Copper is used in wiring because it is a great conductor, both of electricity and heat. Being a solid thermal conductor, copper makes for an excellent exhaust gasket material. The engine’s exhaust heat at the exhaust face of the cylinder head is quickly and easily transferred to the exhaust header tubing via the copper exhaust gaskets to be carried away from the engine via exhaust flow and radiant air flow around the header tubes. Paper-type gaskets are the exact opposite, as paper is an insulator, holding in those high exhaust temperatures. This insulating effect is what burns the exhaust gasket, turning it brittle and causing leaks and blow outs where gasket coverage is thin. 

Paper gaskets also “set” over time, which is why most manufacturers recommend constant header bolt tightening. The bolts aren’t backing out, the gasket is shrinking/setting, and the bolts require tightening to apply clamping force on the paper gaskets again to maintain proper sealing. With the use of ThermoTight dead soft copper header gaskets for your SBC square port heads you won’t have to worry about header bolts being a maintenance issue, as the copper gasket material does not shrink or blow out like paper gaskets do. We even include a full set of zinc plated header bolts in this kit to ensure your installation goes smoothly. ThermoTight copper gaskets work extremely well as copper exhaust manifold gaskets too if you’re having issues sealing original iron exhaust manifolds.

Solve your exhaust gasket sealing problems with our ThermoTight dead soft copper gaskets and put exhaust leaks behind you. Easy to install, reusable, and premium materials at an excellent value that are perfect for high performance engines used in serious street cars or racing and for extensive high heat applications like supercharged or turbocharged builds. What’s not to like? Don’t forget dead soft copper header collector gaskets too for a complete header sealing solution! We offer Shop 3-Bolt Copper Header Collector Gaskets in all popular 3-bolt flange sizes.