Flowtech Headers Chev LS Universal Engine Swap # 11575FLT Headers, 4-1 One-Piece, Stainless Steel, Natural, 3-Bolt Flange, Chevy, Small Block, LS Engine, Pair Header Style: Long tube one-piece Header Material: 304 stainless steel Primary Tube Outside Diameter (in.): 1 5/8 in. Header Color: Natural Flange Style: Standard Weld-Up: No Cylinder Head Port Shape: Round Collector Attachment: 3-bolt flange Collector Diameter (in.): 2.50 Collector Reducers Included: Yes Collector Reducer Exit Diameter: 2.500 in. Tuned: No Flange Thickness (in.): 0.38 in. Bolts/Studs Included: Yes Gaskets Included: Yes Crossover Pipe Included: No Catalytic Converter(s) Included: No Motor Mounts Included: No Transmission Mount Included: No Quantity: Sold as a pair. Flowtech Headers Flowtech headers are designed to provide optimum exhaust flow for increased horsepower, torque, fuel economy, and improved throttle response. Leak-tested for maximum performance, they feature the industry's best welds for durability and are carefully engineered for precise fit. Available for a wide range of applications, they're offered in block hugger, competition, fenderwell, lakester, long tube, mid-length, shorty, upright, and turbo styles. Varying with the application, Flowtech headers are constructed from sturdy and lightweight cold-rolled mild steel or stainless steel for increased strength and durability. All tubing is mandrel-bent to provide consistent tubing diameter for smooth flow and increased exhaust velocity. Extra-thick, machined header flanges provide a leak-free seal and maximum strength. For long-term rust and corrosion-resistance, available finishes include natural and polished stainless steel, high heat-resistant black paint, or a satin silver metallic ceramic thermal barrier coating. All mounting hardware and premium gaskets are included.Important notes: Breaking in an engine with ceramic coated headers WILL result in damage to the coating and will VOID all warranties. Ceramic coated headers require several heat cycles to fully cure before they will withstand extreme heat. Hooker recommends using cast iron exhaust manifolds or old headers to break in new engines to avoid coating damage. Flowtech does not recommend the use of header wraps as this will void the warranty.