1 7/8" 97-2000 C5 Corvette headers. Headers only with adapters to connect to factory exhaust system-cutting and welding is required. Manufactured from 304 Stainless, the headers feature 3/8" thick, CNC laser cut flanges, and CNC mandrel bent 1 7/8" primary tubes. The headers are completely tig welded together, have the AIR tubes and Oxygen sensors installed. The headers have shown gains of 40+ rear wheel horsepower on highly modified engines. The 1 7/8" headers are perfect for large cubic inch, forced induction, or nitrous oxide applications. Also available as part #C5LS178OR with 3" x pipe and off road pipes, or C5LS178CAT with 3" high flow cats and x pipe-either part # will be a bolt on installation.