WCFab's 2001-2004 LB7 Duramax Billet Exhaust Manifolds replace the restrictive factory cast parts with high-strength, TIG-welded high-flow billet steel components. These manifolds are exhaust port gasket matched and internally divided for optimal flow with OEM or ported cylinder heads. Outlet locations allow full compatibility with OEM style up pipes and are paired with WCFab's 2" Stainless High-Flow Up Pipes for optimized performance. Includes new gaskets, ARP 12PT fasteners, and assembly lube for easy install. Finished in Black Ceramic Coat rated for 2000 deg F. Manifold replaces the following GM Part Numbers: 12637647, 12624683, 97224587

• 1/8 NPT ports (and optional plugs) included in driver and passenger side manifold for installation of EGT or drive pressure sensors
• Finished in Black Ceramic Coat rated for 2000 deg F
• Fully TIG Welded, CNC machined billet steel exhaust manifolds
• Includes ARP 12PT Fasteners and Washers
• Includes new gaskets for manifolds & up pipes
• Made in USA