HOOKER COMPETITION FULL-LENGTH HEADERS, BLACK HI-TEMPERATURE PAINT -- 1.625 in. tube diameter, 16-gauge tube wall thickness, 2.5 in. flange collector, 8 in. collector length, 0.3125 in. standard head flange; They include all the necessary hardware for complete installation; Sap shape port; Full-length style; They feature tuned-length primary tubes for maximum exhaust scavenging and velocity, light but sturdy 16-gauge mild steel mandrel-bent tubing for smooth exhaust flow, long transition collector for decreased back pressure, and machined flanges for a perfect seal; Designed for optimal performance and industry's best welds for durability; Exhaust systems can also be fabricated using either Hooker Super Competition Aero Chamber mufflers, Maximum Flow mufflers, Super Competition turbo mufflers, Competition turbo mufflers or header type Hooker mufflers; Equipped with a fitting to accept the stock oxygen sensor; With Hooker's limited warranty.