Truck pullers, mud boggers, and demolition derby drivers know that there’s one major problem with regular exhaust systems: They sit low to the ground. For truck pullers and boggers, this means that the exhaust pipes can become clogged with mud. For those driving in derbies, get hit at the wrong angle and you end up with an exhaust pipe that’s at best restricted if not completely closed off. Clogged with mud or closed off/restricted is bad. In all three of these competitions max power production is vital and anything that restricts or stops up exhaust flow will hinder that. That’s why Holley’s Flowtech Division has introduced these upright headers for all SBC applications.
These Things Look Like They’re Straight Out of Mad Max
These Flowtech upright headers look similar to trucker stacks, except they turn up immediately after exiting the manifold. Trucker stacks leave the engine compartment and usually exit behind the truck cab. While these upright headers do look cool, they’re more function than form. Those two big collectors sticking straight up out of the engine bay are just cool.
They’re Built to Take a Beating, Too
Take a look at the picture above. The CNC-machined header flanges are extra beefy-at least double the thickness of other header flanges-for added strength. This is an important consideration for demolition derby competitors especially.
Flowtech says these headers are designed especially for big cubic inch and big output Small Block Chevy Engines. They’re available with tube diameters of 1 5.8 inch for lower power engines and 1 ¾ inch for engines making more power. The natural stainless steel color tubes are all CNC-mandrel bent. Because of this, the tubes all have consistent diameters to optimize exhaust flow and cylinder scavenging. This helps to ensure that the engine is able to produce every bit of power you built into it.
The collectors on these headers are three-inches in diameter and 12 inches long. Inside the collectors, the exhaust tubes are capped with spear tips that help prevent exhaust back flow and “encourage” the flow of exhaust out of the tubes. This also helps to keep the engine running at optimum efficiency and power output.
Other than the flanges, the headers are made out of heavy duty 16 gauge 409 steel. This gives them extra strength while still looking great. They also resist rust because they’re made from stainless instead of regular steel.