High Flow Exhaust Manifolds & Up Pipes for 01-04 Chevy GMC 6.6L Duramax Diesel

High-flow exhaust manifolds made from cast, high-sil moly and up-pipe bellows internally sleeved from aircraft-grade 304 stainless steel with increased inner diameter for higher flow designed for 2001–2004 Chevy and GMC 6.6L Duramax LB7 diesel engines. This kit improves exhaust flow to the turbocharger, reduces restriction, and restores reliable exhaust sealing. Ideal for replacing cracked manifolds, leaking up pipes, or restrictive factory components, this high flow exhaust manifold and up pipes kit supports better turbo efficiency, improved drivability, and long-term durability.

Fitment

• 2001–2004 Chevrolet Silverado 2500HD, 2500, 3500HD, 3500 -- LB7
• 2001–2004 GMC Sierra 2500HD, 2500, 3500HD, 3500 -- LB7

Product Details

• Manifolds: Cast, high-sil moly construction
• Up-Pipes: 11 gauge 304 stainless steel with internally sleeved aircraft-grade 304 stainless steel bellows and increased inner diameter
• Flow Improvement: 53% greater flow over stock
• Emissions: 50 States Emissions Legal (E.O. D-701-34)
• Performance: Designed to maximize power and flow characteristics, lower exhaust gas temperatures (EGTs) and accelerate turbo spool-up while increasing power, fuel economy, and maintaining reliability
• Kit Contents: Two exhaust manifold gaskets, two up-pipe to turbo gaskets, two up-pipe to manifold gaskets, and bolts
• Ceramic Coating Option: Available to enhance the existing benefits of the high-flow exhaust manifold and up-pipes kit

Installation

The factory downpipe (2001-2004 LB7 only) does not fit aftermarket manifolds and up-pipes—a separate aftermarket 3-inch down pipe is required. Installation requires removal of factory exhaust components and manifold mounting bolts; professional installation is recommended.

Check local emissions regulations before purchase. Professional installation is recommended.

Get the right part the first time.