Wehrli 01-04 Chevrolet 6.6L Duramax LB7 2in Stainless Pass. Side Up Pipe w/Gaskets (Single Turbo)Replace the lightweight 16G, leak prone passenger side OEM up pipe in your 2001 2004 6. 6L LB7 Duramax with this heavy duty 11 gauge 2" Stainless up pipe from WCFab. Our HD Stainless Bellow that will not crack and leak like OEM. Larger diameter and better flow than stock helps to increase Turbo spool up and decrease EGTs. This up pipe is built to clear a conventional downpipe behind the engine in single turbo applications with the mounting location in