If you’re as serious about your having fun as we are about exhaust systems, than our new Flowtech upright headers are just the ticket for you! Our new upright Headers are the perfect combination of quality and value. We start by using heavy duty 16-gauge 409 Stain-less Steel tubing for corrosion resistance and durability. The primary tubes are mandrel-bent on a CNC machine providing consistent tubing diameters and reducing air flow restrictions. These improvements increase the cylinder scavenging effect, improving the overall breathing capability of your engine. Flowtech upright headers are available in 2 versions for Small Block Chevys. The 1-5/8” primary tube design is perfect for most stock and mild cam engines. If you’re running a stroker motor or have a compression ratio above 12:1 we recommend our 1-3/4” primary tube headers. Both versions feature a 3” merged collector along with a welded-in collector spear to make the transition from the primary tubes to the collector as smooth as possible. These components help to improve the flow and performance of the header, maintaining exhaust velocity and improving volumetric efficiency. Flowtech uses a 3/8” thick header flange for years of leak-free performance. And the primary tubes are TIG welded to the flanges increasing the overall strength and durability of the headers. So whether you’re running a derby car at the county fair, your hooked to a pulling sled, or just getting down and dirty in the mud, Flowtech’s new upright headers are the perfect combination of functionality and performance no matter what you choose to drive. Upright headers are designed for use in Non-Emissions Controlled Vehicles and Racing Vehicles only. Flowtech headers and header accessories are available anywhere Holley products are sold.