Wehrli Custom Fab WCFab Billet Exhaust Manifold Kit for 2017-2025 Chevrolet/GMC 2500HD/3500HD (6.6L L5P Duramax)

Fits select 2017-2025 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD (6.6L L5P Duramax).

WCFab Billet Exhaust Manifolds replace restrictive factory cast components with high-strength, CNC-machined billet steel units for improved exhaust flow and durability. These manifolds are exhaust port gasket matched and internally divided to optimize flow for both OEM and ported cylinder heads. Designed for high-performance applications, they are fully TIG-welded and finished in a black ceramic coating rated for up to 2000°F. The design maintains full compatibility with the vehicle emissions system, including a necessary EGR riser flange and sensor ports.

• CNC-machined billet steel construction, fully TIG-welded
• Internally divided for optimal exhaust flow and velocity
• Black ceramic coat finish rated for 2000°F heat resistance
• 1/8 NPT ports and plugs included for EGT or drive pressure sensors
• Includes ARP 12PT fasteners and washers for cylinder head installation
• Compatible with OEM-style up pipes; designed to pair with WCFab 2-inch Stainless High-Flow Up Pipes
• Includes new manifold-to-head and manifold-to-up-pipe gaskets
• Manufacturer Part Number: WCF100373

Note: Up-pipe fastener kits are sold separately (MPN: WCF100199).