2004 GTO SLP Headers, Coated 1-3/4" Long-Tubes w/High-Flow Cats/Downpipes ,shipping is not included. Developed to meet the needs of even the most heavily modified GTO applications, these headers employ 1 3/4" primaries and 3" collectors to provide huge power increases throughout the rpm range. Team them up with one of SLP's Loud Mouth or PowerFlo cat-backs to create a fully optimized exhaust system. Race-proven on SLP's 575-hp ZL-402 development car! GTO Long-Tube Header Features * Constructed entirely from mandrel-bent 409 stainless steel * Heavy-duty (3/8"), one-piece flanges resist warping * Worth up to 25 additional rear-wheel horsepower * Aluminum-ceramic coating provides superior performance, appearance, and component longevity * Easy bolt-on installation?no cutting or welding required! * Compatible with stock or SLP cat-back system * Includes high-flow catalytic converters, oxygen-sensor extension harnesses, detailed instructions, and all required installation hardware