Wehrli 01-04 Duramax LB7 Billet Exhaust Manifold & SS Up Pipes w/ Gaskets and ARP HardwareWCFab'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