High Flow Exhaust Manifold for 2017–2025 Chevy GMC 6.6L Duramax L5P Diesel

This High Flow Exhaust Manifold for 2017–2025 Chevy and GMC trucks equipped with the 6.6L Duramax L5P diesel is made from cast, high-sil moly and is engineered to improve exhaust flow, reduce restriction, and support better turbo response. The manifold and up-pipe exhaust system are 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. Built for heavy-duty diesel use, this manifold is a reliable upgrade for replacing cracked, leaking, warped, or restrictive factory-style components and is suitable for daily driving, towing, hauling, and performance-focused Duramax applications.

Fitment

• 2017–2019 Chevrolet Silverado 2500/3500 HD -- 6.6L Duramax L5P
• 2017–2019 GMC Sierra 2500/3500 HD -- 6.6L Duramax L5P
• 2020–2025 Chevrolet Silverado 2500/3500 HD -- 6.6L Duramax L5P
• 2020–2025 GMC Sierra 2500/3500 HD -- 6.6L Duramax L5P

Product Details

• Material: Cast high-sil moly construction
• Up-Pipe Construction: Aircraft-grade 304 stainless steel bellows with internally sleeved design and increased inner diameter for higher flow
• Up-Pipe Wall Thickness: .120-inch wall thickness with 2-inch outside diameter
• Performance Benefits: Lowers exhaust gas temperatures (EGTs), accelerates turbo spool-up, and increases power and fuel economy
• EGT Port: Pre-molded and tapped for EGT gauge sensor installation
• Hardware: Includes 16 exhaust manifold mounting bolts

Installation

This is a direct-fit replacement for factory manifolds on 2017–2025 models. Professional installation is recommended to ensure proper sealing and turbo response optimization. Remove factory manifolds and bolt-on this high flow exhaust manifold assembly using OEM or upgraded fasteners.

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

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