Wehrli 100589 Stainless Up Pipe Kit with Gaskets (Twin Turbo), 2in, | 2001-2004 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LB7

Features:

• Fits 2001–2004 6.6L Duramax LB7 engines
• Designed for twin turbo applications
• Replaces leak-prone 1 5/8 inch factory pipes
• Constructed from heavy-duty 11-gauge stainless
• Features high-strength stainless steel bellows
• Improves turbo spool and throttle response
• Helps reduce exhaust gas temperatures (EGTs)
• Includes gaskets for a complete install
• Not compatible with conventional downpipes
• Works with factory exhaust manifolds
• 2-inch diameter for increased exhaust flow

Ditch the Leaks and Unlock Better Flow

If you're running a twin turbo setup on your 2001 to 2004 LB7 Duramax, the last thing you want is a restrictive or failure-prone up pipe choking performance. The Wehrli 100589 Stainless Up Pipe Kit is built to replace the weak 1 5/8-inch factory pipes with heavy-duty 2-inch tubing that’s designed to handle high heat and pressure without flinching. These pipes are made from thick 11-gauge stainless steel and come with robust stainless bellows that resist cracking and leaking—one of the most common issues with the stock design. With a stronger, smoother path for exhaust gases, you'll see quicker turbo spool-up and cooler EGTs, both of which are major wins for power and reliability.

Built for Boost, Not for Compromise

This kit is tailored specifically for twin turbo applications using the factory exhaust manifolds. The design is nearly symmetrical on both sides and eliminates the factory-style indents that normally allow space for a rear-mounted downpipe. That means you get more consistent flow and fewer bottlenecks in the exhaust path, but it also means these pipes won’t work with a conventional downpipe routed behind the engine. Installation is made easier with the included gaskets, and once everything is bolted up, you're left with a strong, leak-free connection that can handle serious boost and temperature without breaking a sweat. Whether you're finishing a custom twin turbo build or upgrading a worn-out setup, this up pipe kit is the kind of upgrade that pays off every time you get into the throttle.

Fits: 2001, 2002, 2003, 2004 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LB7