This proven incorporates equal length runners and a true 3 into 1 F1 style merge collector. The header system also utilizes a German made 200 cell metal matrix sport catalyst which is OBD2 compliant ( No CEL Lights). Made with highest quality T304 Stainless Steel that is Tig welded by hand. The system also incorporates CNC machined flanges and both at the cylinder head and at the muffler connection. The World Challenge Sport header system is designed to work with the Factory mufflers and is a direct replacement system.