Frequently Asked Questions

Are custom headers difficult to build by myself?

Definitely not! Although it may be daunting initially, building headers can be broken into just a few simple steps. With the right prep work, and of course superior materials made in the USA, our header build kits are the optimum solution to all your header builds. We offer phone and email support every business day to talk you through any design or build difficulties you may encounter during the process. We also have a 6-part video series here to coach you through the steps necessary in header design and fabrication.

Why should I opt for a performance slip-on merge collector instead of a standard weld-on formed collector with my header build kit?

Although a bit more expensive, the hand made, purge-Tig welded slip on merge collectors offer many advantages when compared to a standard formed collector. Our merge collectors are perfectly sized and toleranced to slide tightly over your header's primary tube at the collector inlets. No more messing around with trying to line up a collector star or spike and worry about exhaust leaks at the collector. The integrated merge spike in the collector is also integrated to the collector, reinforcing the collector's strength, and creating a smooth laminar flow for the exhaust. When properly installed, your merge collectors' internal spikes are also excellent scavenging inducers, creating a smooth vortex of gases at the merge point, increasing exhaust velocity and pulling the gases through the primary tubes quicker. This increased exhaust gas flow means less exhaust residual resides in your engine's combustion chamber, thereby increasing volumetric efficiency, allowing more air (oxygen) into the cylinder, which means more fuel can be burned per revolution, meaning greater power can be achieved.

How do I calculate my header size?

We figure primary tube size as well as collector size through various methods, though our combined decades of experience have given us an edge over many common misconceptions.

Check out our header calculations page for general rules of thumb, and some basic equations for figuring out some starting points on header sizing, collector sizing, turbo charger selection, and more.

Prop 65 Information

For more information regarding Proposition 65 and California's requirements, visit their website: