Improve airflow, performance, and reliability on your 2001–2016 GM 6.6L Duramax with MFM’s Stainless Steel Performance Exhaust Manifold Kit. Engineered to outperform restrictive stock manifolds, MFM’s manifolds provide increased exhaust flow, lower drive pressure, and faster turbo spool-up for a noticeable improvement in both power and efficiency. Built from durable stainless steel, these manifolds deliver long-term strength and heat resistance under the harshest towing and performance conditions.

MFM’s designs this kit to maximize airflow with up to 55 percent more flow over OEM manifolds, helping to reduce EGTs and maintain reliable performance under load. Each kit includes both driver and passenger manifolds, premium gaskets, and upgraded hardware for a straightforward installation. Whether towing, daily driving, or upgrading performance, MFM’s delivers a stronger, cooler-running Duramax exhaust system.

Features:

• Reduces exhaust back pressure for improved engine efficiency
• Durable stainless steel build ensures long-lasting performance
• Flows up to 55 percent more air compared to factory manifolds
• Improves turbo spool-up response while lowering overall EGTs
• Enhances towing capability and everyday drivability reliability
• Direct-fit design replaces restrictive OEM factory manifolds
• Lowers drive pressure to improve durability under heavy loads
  

Specifications:

• Brand: MFM
• Material: Stainless Steel
• Flow Increase: Up to 55 Percent Over Stock
• Design: High-Flow Exhaust Manifold
• EGT Reduction: Yes
• Drive Pressure Reduction: Yes
• Turbo Spool Improvement: Yes
• Installation Type: Direct Bolt-On
• Engine: 6.6L Duramax Diesel (LB7 / LLY / LBZ / LMM / LML)

Included:

• (1) Driver Side Exhaust Manifold 
• (1) Passenger Side Exhaust Manifold 
• (2) Exhaust Manifold Gaskets
• Up Pipe Bolts 10mm x 30mm x 1.5mm 
  

Fitment:

• 2001–2016 GMC Sierra 2500 6.6L Duramax Diesel
• 2001–2016 GMC Sierra 3500 6.6L Duramax Diesel
• 2001–2016 Chevrolet Silverado 2500 6.6L Duramax Diesel
• 2001–2016 Chevrolet Silverado 3500 6.6L Duramax Diesel

Notes:

• 1 Year Warranty
• This product cannot be shipped to California
  
• These exhaust manifolds will ONLY work with OEM length up pipes
• Manifolds will NOT work with OEM bolts, requires 10mm X 30mm X 1.5mm bolts that are NOT included. We include 1 allen head bolt that is used near the flange on one manifold due to tight clearances.