Fits 2017-2019 Chevrolet Silverado and GMC Sierra 2500HD / 3500HD (6.6L L5P Duramax).

The factory plastic coolant reservoirs on the L5P Duramax are prone to yellowing and becoming cloudy over time, which detracts from your engine bay's appearance. More critically, the OE units feature integrated, non-replaceable level sensors that frequently fail, triggering persistent false "low coolant" warnings that require the replacement of the entire tank assembly. The WCFab Fabricated Aluminum Coolant Tank Kit addresses these issues with a durable, American-made solution designed to mount in the factory location.

Constructed from high-quality aluminum and finished in a Gloss White powder coat, this kit features a serviceable float-type low coolant level sensor and a billet aluminum sight glass for easy fluid monitoring. This design ensures that if the sensor ever fails, it can be replaced individually without discarding the entire tank. The kit comes complete with a black anodized billet aluminum cap and all necessary installation hardware.

• Fabricated aluminum construction for superior durability
• Billet aluminum coolant level sight glass
• Serviceable low coolant level sensor eliminates common OE failure point
• Gloss White powder coat finish
• Includes black anodized billet aluminum cap and overflow hose
• Direct replacement for GM Part Numbers: 84257137, 84214124, 84138913, 84174037
• Made in USA
• Manufacturer Part Number: WCF100433-GW

Fits 2017-2019 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD models (6.6L L5P Duramax).

The factory plastic coolant reservoirs on the L5P Duramax are prone to yellowing and clouding over time, making fluid levels difficult to read and detracting from the engine bay's appearance. More critically, the OE units feature non-replaceable sensors that often fail prematurely, triggering false low coolant warnings that require the replacement of the entire tank assembly. This Wehrli Custom Fabrication (WCFab) kit provides a permanent solution by mounting a durable, fabricated aluminum tank in the factory location.

This kit upgrades your cooling system with a high-quality float-type sensor that is fully serviceable, ensuring you never have to replace the whole tank due to a sensor malfunction again. Constructed in the USA and finished in a resilient gloss black powder coat, this kit includes a billet aluminum sight glass for quick level checks and a black anodized billet cap for a premium seal.

• Direct replacement for GM Part Numbers: 84257137, 84214124, 84138913, 84174037
• Fabricated aluminum construction with gloss black powder coat finish
• Integrated billet aluminum coolant level sight glass
• Serviceable low coolant level sensor eliminates common OE failure point
• Includes black anodized billet aluminum cap and overflow hose
• Complete with all necessary installation hardware
• Made in the USA
• Manufacturer Part Number: WCF100433-GB

Fits 2017-2019 Chevrolet Silverado and GMC Sierra 2500/3500 HD (6.6L).

The WCFab Fabricated Aluminum Coolant Tank Kit for the L5P Duramax provides a durable, professional-grade solution to the common issues found with factory plastic reservoirs. Over time, original equipment (OE) tanks are prone to yellowing and clouding, making it difficult to monitor fluid levels and detracting from the engine bay's appearance. More critically, the factory units feature non-replaceable sensors that often fail, triggering false low-coolant warnings and requiring the replacement of the entire reservoir assembly.

This Wehrli Custom Fabrication kit (MPN WCF100433-FB) mounts directly to the OEM location and utilizes a serviceable, high-quality float-type sensor for long-term reliability. Constructed from heavy-duty aluminum and finished in a flat black powder coat, the tank includes a billet aluminum sight glass for quick visual checks and a black anodized billet cap for a clean, finished look.

• Direct replacement for GM part numbers: 84257137, 84214124, 84138913, 84174037
• Fabricated aluminum coolant tank with flat black powder coat
• Billet aluminum coolant level sight glass for easy monitoring
• Serviceable low-coolant level sensor (float-type)
• Black anodized billet aluminum cap included
• Includes installation hardware and overflow hose
• Made in the USA

Fits select 2015-2019 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD models (6.6L).

The WCFab Lower Splash Shield Kit replaces the vulnerable factory plastic components covering the lower engine bay and cooling stack. Engineered for maximum durability, this heavy-gauge aluminum shield provides superior coverage and protection against road debris while maintaining a clean, professional appearance under the chassis. The kit is specifically designed to fit both gas and diesel HD models, offering significantly more front coverage area than the original equipment.

Installation is straightforward using basic hand tools, as the shield utilizes existing OEM mounting points. The design features built-in standoffs for frame mounting and includes dedicated brackets to provide proper support for the lower radiator hose. Each kit is finished in a durable Fine Texture Black powder coat to match factory plastics and includes all necessary flanged head mounting hardware.

• Manufacturer Part Number: WCF100432-FTB
• Constructed from heavy-gauge aluminum for increased impact resistance
• Durable Fine Texture Black powder coat finish
• Incorporates lower radiator hose support brackets
• Built-in standoffs for precise frame mounting
• Includes new flanged head mounting hardware
• Made in USA

Fits 2015-2019 Chevrolet Silverado 2500 HD and 3500 HD (High Country, LT, LTZ, and WT) models.

Removing the factory plastic lower bumper valance is a common modification for 2015-2019 Silverado HD owners looking to improve ground clearance or accommodate oversized wheel and tire packages. However, this often leaves an unfinished gap in the center of the bumper. The Wehrli Lower Valance Filler Panel solves this issue by cleanly finishing the lower center cutout with a rugged, professional look.

Constructed from heavy-gauge aluminum, this panel is designed specifically for trucks equipped with factory tow hooks. The fine texture black powder coat finish is selected to match existing OEM trim plastics for a seamless factory-style appearance. Installation is straightforward and utilizes your vehicle's existing hardware.

• Fabricated from heavy-gauge aluminum for durability and corrosion resistance.
• Fine Texture Black powder coat finish matches OEM plastic trim components.
• Precision cutouts maintain full access to factory-installed tow hooks.
• Allows for improved approach angles and clearance for aggressive tire fitment.
• Reuses existing factory hardware for a secure, bolt-on installation.
• Manufacturer Part Number: WCF100427-FTB.

Fits 2015-2019 Chevrolet Silverado 2500 HD and 3500 HD (all trims).

Removing the factory plastic lower bumper valance is a proven method for improving ground clearance and accommodating aggressive wheel and tire combinations on 2015-2019 Chevy HD trucks. However, air dam removal leaves an unattractive, gaping void in the lower center section of the bumper. The Wehrli Custom Fabrication (WCFAB) Lower Valance Filler Panel solves this issue, providing a finished, professional look to your lifted or leveled truck.

Constructed from heavy-gauge aluminum, this panel is designed specifically for trucks equipped with tow hooks. The precision cutouts ensure you maintain full access to your factory recovery points while cleaning up the front-end aesthetics. The raw aluminum finish is ready for install as-is or provides an ideal surface for custom paint matching to your vehicle's color code.

• Replaces the void left by removing the OEM plastic lower bumper valance
• Precision-cut for access and use of factory-installed tow hooks
• Heavy-gauge aluminum construction for durability and corrosion resistance
• Raw aluminum finish suitable for paint matching or powder coating
• Bolts up using existing factory hardware for a straightforward installation
• Manufacturer Part Number: WCF100425

Fits select 2006-2010 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD (6.6L LBZ/LMM Duramax). This Wehrli Custom Fabrication (WCFab) Top Outlet Billet Thermostat Housing and Upper Coolant Pipe Kit replaces the restrictive factory upper radiator hose and coolant return pipe. By rerouting the coolant upward and forward from the thermostat, this kit clears the driver-side valve cover area to improve access to fuel system components and provide necessary clearance for larger aftermarket turbochargers.

• CNC Machined Billet Aluminum Thermostat Upper Housing
• Improves clearance for valley-mounted S300/S400 SXE and race cover style turbochargers
• Compatible with factory VGT style turbochargers
• Replaces GM Part Numbers 19330105, 15792824, 25833204, and 97361881
• WCFab Red custom powder coat finish
• Includes heavy-duty silicone boots and stainless steel T-bolt clamps
• Designed for single CP3 setups (MPN: WCF100420-RED)

Fits 2006-2010 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD (6.6L Duramax LBZ/LMM).

This Wehrli Custom Fabrication (WCFab) Top Outlet Billet Thermostat Housing and Upper Coolant Pipe Kit is designed to optimize engine bay space and cooling efficiency on LBZ and LMM Duramax engines. By rerouting the coolant flow upward and forward from the thermostat, this kit eliminates the factory upper radiator hose that typically obstructs the driver-side valve cover and coolant return pipe. This revised layout is essential for mounting race cover style or BorgWarner SXE turbochargers in the valley, providing the necessary clearance for larger aftermarket setups and improved access to fuel system components.

The kit features a precision CNC-machined billet aluminum thermostat upper housing finished in a durable Gloss Black powder coat. It remains fully compatible with factory VGT style turbochargers and is configured for single CP3 pump setups.

• CNC Machined Billet Aluminum Thermostat Upper Housing
• Gloss Black Powder Coat Finish
• Includes Coolant Pipe, Silicone Boots, and T-Bolt Clamps
• Improves clearance for S400 and SXE frame turbochargers
• Replaces GM Part Numbers: 19330105, 15792824, 25833204, 97361881
• Manufacturer Part Number: WCF100420-GB

Fits select 2020-2025 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD models equipped with the 6.6L L5P Duramax engine.

The Wehrli Custom Fab (WCFab) Stage 3 High Flow Bundle is a comprehensive solution to the airflow and reliability bottlenecks found in the factory L5P Duramax air track. This kit replaces the restrictive OEM resonator and prone-to-fail middle boot joints with heavy-duty components designed for high-boost environments and improved thermal efficiency. By upgrading both the intake and exhaust sides of the turbo system, this bundle eliminates horsepower-robbing boost leaks and reduces exhaust gas temperatures (EGTs).

The 4-inch aluminum intake pipe features a surge ring and connects to a dedicated air box enclosure with a high-flow dry filter and Outerwears pre-filter. On the charge side, the 3.5-inch cold side pipe utilizes a CNC-machined flange with a double O-ring seal to ensure a leak-free connection, while the 3-inch hot side pipe provides a direct path for compressed air. The package is completed with a 3.5-inch ceramic-coated and heat-wrapped downpipe that mates directly to the DOC outlet and factory exhaust system.

• 4 in. Aluminum intake pipe with air box enclosure and dry filter assembly
• 4 in. Intake horn with PCV port and surge ring
• 3.5 in. Cold side intercooler pipe (Passenger side) with CNC machined flange
• 3 in. Hot side intercooler pipe
• 3.5 in. Ceramic coated and heat-wrapped downpipe
• High-quality reinforced silicone boots and stainless steel T-bolt clamps
• Outerwears pre-filter cover included
• Retains factory connection points and all OEM sensors
• No tuning required; direct bolt-on installation
• Finished in WCFab signature Gloss White powder coat
• Made in the USA
• Manufacturer Part Number: WCF100418-GW

Fits select 2020-2025 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD models with the 6.6L L5P Duramax engine.

This Wehrli Custom Fabrication (WCFab) High Flow Intake Bundle Kit is a comprehensive air management upgrade designed to replace the restrictive factory intake and intercooler plumbing. By increasing the turbo inlet diameter to 4 inches and replacing the plastic/rubber OEM components with heavy-duty mandrel-bent aluminum, this kit optimizes airflow and significantly improves durability under high boost levels. The system is designed to bolt directly to factory mounting points and retains all OE sensors without the need for aftermarket tuning.

The package includes a Stage 2 intercooler pipe upgrade, replacing the 2.5-inch resonator-equipped driver-side (hot) pipe and the leak-prone 2-piece passenger-side (cold) pipe. The new 1-piece 3-inch hot-side and 3.5-inch cold-side pipes utilize CNC-machined flanges with double O-rings and high-quality silicone boots with stainless steel T-bolt clamps to eliminate boost leaks and ensure a secure connection even in high-performance applications.

• Manufacturer Part Number: WCF100414-RED
• 4 in. Mandrel-bent aluminum intake pipe and air box enclosure
• 3 in. Driver-side (Hot Side) intercooler pipe
• 3.5 in. Passenger-side (Cold Side) intercooler pipe
• Heavy-duty 14 ga. aluminum construction for maximum durability
• WCFab Dry Filter assembly with Outerwears hydrophobic pre-filter cover
• Eliminates OEM clip-ring design at Y-bridge for a superior silicone boot connection
• Retains factory connection points and MAF/PCV sensors
• Finished in a premium Illusion Cherry custom powder coat
• Made in the USA

The WCFab High Flow Intake Bundle Kit for the 2020-2025 Chevrolet Silverado and GMC Sierra 2500/3500 HD (6.6L L5P Duramax) is a comprehensive airflow solution designed to eliminate the restrictions of factory intake and intercooler plumbing. This kit replaces the narrow OEM intake and the leak-prone plastic/rubber intercooler pipes with heavy-duty, oversized aluminum components for improved durability and optimized flow.

• Air Intake: Includes a 4 in. mandrel-bent aluminum intake pipe, air box enclosure, and dry filter assembly with a hydrophobic Outerwears pre-filter cover. The 4 in. intake horn features a PCV port and surge ring.
• Intercooler Piping: Upgrades the hot side to a 3 in. diameter 1-piece pipe and the cold side to a 3.5 in. diameter pipe. The 3 in. hot side pipe eliminates the restrictive OEM clip ring at the Y-bridge in favor of a silicone boot and T-bolt clamp for a leak-free seal under high boost.
• Construction: All pipes are fabricated in the USA from 14-gauge aluminum with smooth mandrel bends and finished in a Gloss White powder coat.
• Components: CNC machined flanges with double O-rings, high-quality silicone boots, stainless steel T-bolt clamps, and all necessary installation hardware.

This kit is a direct bolt-on upgrade that retains factory connection points and sensors. No aftermarket tuning is required for installation. Part Number: WCF100414-GW.

Fits 2020-2025 Chevrolet Silverado and GMC Sierra 2500/3500 HD (6.6L L5P Duramax).

The Wehrli Custom Fabrication (WCFab) Stage 2 High Flow Bundle Kit provides a complete overhaul of your L5P Duramax's induction and charge air system. This kit replaces the restrictive, multi-piece factory components with high-flow, 14-gauge mandrel-bent aluminum tubing. By upgrading the intake and intercooler piping, you eliminate common failure points such as the leak-prone plastic passenger-side cold pipe and the restrictive resonator-equipped driver-side hot pipe.

The included 4-inch intake features a high-flow turbo inlet horn and a sealed air box with a removable lid for easy inspection. For the intercooler side, WCFab upgrades the hot side to 3 inches and the cold side to 3.5 inches, utilizing CNC-machined flanges with double O-rings to ensure a leak-free seal under high boost pressures. Finished in a durable WCFab Grey powder coat, this kit is a complete bolt-on solution that requires no aftermarket tuning.

• 4 in. Aluminum intake pipe with sealed air box enclosure and dry filter
• Outerwears hydrophobic pre-filter cover included to protect the MAF sensor and turbo
• 4 in. Intake horn with PCV port and Surge Ring
• 3 in. Mandrel-bent hot side intercooler pipe (replaces 2.5 in. factory unit)
• 3.5 in. Mandrel-bent cold side intercooler pipe (replaces plastic/rubber factory unit)
• CNC machined flanges with double O-rings for superior sealing
• Heavy-duty 14-gauge aluminum construction with silicone boots and stainless steel T-bolt clamps
• Custom WCFab Grey powder coat finish
• No tuning required; retains factory connection points and sensors
• Manufacturer Part Number: WCF100414-GRY

Fits select 2020-2025 Chevrolet Silverado and GMC Sierra 2500/3500 HD models (6.6L L5P Duramax).

The Wehrli Custom Fab (WCFab) High Flow Intake Bundle Kit is a comprehensive induction solution designed to eliminate the flow restrictions of the factory L5P setup. This Stage 2 kit replaces the OEM intake and the leak-prone plastic/rubber intercooler pipes with heavy-duty 14-gauge mandrel-bent aluminum components. The 4-inch turbo inlet pipe is paired with an air box enclosure and a dry filter assembly, protected by a hydrophobic Outerwears pre-filter cover to keep your MAF sensor and turbocharger free of contaminants.

Beyond the intake, this bundle upgrades the restricted 2.5-inch driver-side (hot) pipe and the 2-piece passenger-side (cold) pipe with 3-inch and 3.5-inch diameter alternatives. By utilizing CNC-machined flanges with double O-rings and high-quality silicone boots with stainless steel T-bolt clamps, this kit provides a superior seal capable of holding higher boost pressures than the factory clip-ring design. This is a complete bolt-on upgrade that requires no aftermarket tuning.

• 4 in. Aluminum intake pipe with air box enclosure and dry filter assembly
• 3 in. Driver-side (Hot Side) intercooler pipe
• 3.5 in. Passenger-side (Cold Side) intercooler pipe
• Hydrophobic Outerwears pre-filter cover included
• Heavy-duty 14 ga. aluminum construction with smooth mandrel bends
• CNC-machined flange with double O-rings for a leak-free seal
• Replaces restrictive factory plastic and rubber piping
• Retains factory connection points and sensors
• No tuning required for installation
• Custom Gloss Black powder coat finish
• Made in the USA
• Manufacturer Part Number: WCF100414-GB

Fits select 2020-2025 Chevrolet Silverado and GMC Sierra 2500 HD and 3500 HD (L5P Duramax).

The WCFab High Flow Intake Bundle Kit is a comprehensive Stage 1 upgrade engineered to optimize airflow between the turbo and the engine. By replacing the restrictive factory intercooler pipes, this kit improves turbo spool-up, throttle response, and overall efficiency while eliminating common failure points that lead to power-robbing boost leaks. This bolt-on system is compatible with stock trucks and requires no aftermarket tuning.

This kit replaces the undersized 2.5-inch OEM driver-side (hot side) pipe and the failure-prone plastic/rubber passenger-side (cold side) pipe. WCFab utilizes heavy-duty 14-gauge mandrel-bent aluminum for maximum durability under high boost. The 3-inch hot side pipe eliminates the factory resonator and middle boot joint, reducing turbulence. The 3.5-inch cold side pipe features a CNC-machined flange with a double O-ring seal, replacing the weak factory clip-ring design for a superior seal at the Y-bridge.

• Driver Side (Hot Side) Pipe: 3 in. diameter 14 ga. aluminum; eliminates OEM resonator.
• Passenger Side (Cold Side) Pipe: 3.5 in. diameter 14 ga. aluminum; CNC-machined flange.
• Construction: Smooth mandrel bends with custom WCFab Red powder coat finish.
• Hardware: Includes heavy-duty reinforced silicone boots and stainless steel T-bolt clamps.
• Reliability: Replaces leak-prone plastic components with high-strength aluminum.
• Installation: Bolt-on fitment; retains all factory connection points and sensors.
• MPN: WCF100410-RED

Fits 2020-2025 Chevrolet Silverado 2500/3500 HD and GMC Sierra 2500/3500 HD models equipped with the 6.6L L5P Duramax engine.

The WCFab High Flow Intake Bundle Kit is a comprehensive Stage 1 upgrade designed to eliminate the restrictive and failure-prone factory piping on the L5P Duramax. This kit replaces the 2.5-inch factory hot side pipe and the multi-piece plastic/rubber cold side pipe with heavy-duty aluminum components to optimize airflow between the turbo and the engine. By removing the OEM resonator and secondary boot joints, this bundle improves efficiency, throttle response, and turbo spool-up.

Engineered for high-performance and heavy-duty applications, these pipes are manufactured in the USA from 14-gauge mandrel-bent aluminum. The 3.5-inch passenger side pipe features a CNC-machined flange with a double O-ring seal, replacing the weak OEM clip ring design at the Y-bridge with a robust silicone boot and stainless steel T-bolt clamp connection to handle increased boost pressures without leaking.

• 3 in. Driver Side (Hot) Intercooler Pipe: 1-piece mandrel-bent design eliminates the factory resonator and middle boot joint.
• 3.5 in. Passenger Side (Cold) Intercooler Pipe: Oversized diameter for maximum airflow efficiency.
• Construction: High-strength 14-gauge aluminum tubing finished in Gloss Black powder coat.
• Reliable Sealing: Includes high-quality reinforced silicone boots, stainless steel T-bolt clamps, O-rings, and intercooler outlet clip.
• Installation: Retains factory connection points and sensors; compatible with stock trucks with no tuning required.
• Manufacturer Part Number: WCF100410-GB

This Wehrli Custom Fabrication (WCFab) high-pressure line kit is engineered for 6.6L LML Duramax engines undergoing a CP3 conversion. Specifically designed to support the fueling requirements of high-performance builds, this kit provides a significant increase in fuel volume compared to standard Street Series lines.

The WCF100402 kit features a high-pressure line and rail fitting with a larger inner diameter (I.D.) to maximize flow. This increased bore size is essential for owners running high-output 10mm, 12mm, or 14mm CP3 stroker pumps where factory-sized lines may become a restriction. The included #10 triple square socket ensures you have the specialized tool required for the rail plug during installation.

• Larger I.D. high-pressure fuel line for increased fuel volume
• Enlarged high-pressure rail fitting to support maximum flow
• Recommended for 10mm, 12mm, and 14mm CP3 pumps
• Includes specialized #10 Triple Square Socket for rail plug
• Complete with high-pressure rail plugs and caps
• Manufacturer Part Number: WCF100402

Fits 1998-2010 Dodge Ram 2500 and 3500 (Cummins).

Replace the fragile factory plastic cap in your engine bay with the Wehrli Custom Fabrication (WCFab) Billet Aluminum Oil Fill Cap. Unlike simple slip-on covers, this is a complete, standalone replacement cap CNC-machined in the USA from high-grade billet aluminum. It features a clear anodized finish for superior corrosion resistance and a professional look that lasts.

This cap installs in seconds and includes a new O-ring seal to ensure a proper, leak-free seat. It is designed to match the fitment of the factory component precisely while providing the durability of machined metal.

• CNC machined billet aluminum construction
• Clear anodized finish for long-term protection
• Direct OEM replacement (not a cover)
• Includes new O-ring seal
• Proudly Made in the USA
• Manufacturer Part Number: WCF100394

Note: Not compatible with WCFab X D&J Billet Valve Covers (model WCF100330 or WCF100366). Fitment with other aftermarket billet valve covers is not guaranteed.

Fits select 2020-2025 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD (6.6L L5P Duramax).

Upgrade your L5P Duramax's charge air system with the Wehrli Custom Fab 3.5-inch High Flow Passenger Side Intercooler Pipe. This one-piece upgrade replaces the restrictive factory two-piece plastic pipe, which is prone to failure under increased boost. Constructed from 14-gauge aluminum, this cold-side pipe is designed to handle higher boost pressures while increasing reliability and eliminating the common issue of blown factory boots and boost leaks.

The assembly features a CNC-machined flange with a double O-ring seal for a precision fit against the intercooler. It replaces the OEM clip ring design with a high-quality silicone boot and black anodized billet aluminum adapter, secured by stainless steel T-bolt clamps. This kit is a direct bolt-on solution for stock trucks and requires no additional tuning or modifications.

• 3.5-inch 14-gauge aluminum construction with Gloss White finish
• One-piece design replaces factory two-piece plastic unit
• CNC-machined flange with double O-ring seal
• Incorporated threaded bung for OEM Intake Temperature Sensor
• Upgraded silicone boot and black anodized billet aluminum adapter
• Includes stainless steel T-bolt clamps and new intercooler outlet retaining clip
• Manufacturer Part Number: WCF100381-GW

Fits select 2020-2025 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD models (6.6L L5P Duramax).

Eliminate the weak link in your induction system with the Wehrli Custom Fab 3.5" High Flow Passenger Side Intercooler Pipe. This heavy-duty upgrade replaces the failure-prone, two-piece factory plastic pipe with a single-piece, 14-gauge aluminum construction designed to withstand significantly higher boost pressures. By swapping the problematic OEM clip ring design for a CNC-machined billet aluminum adapter and high-quality silicone boots secured by stainless steel T-bolt clamps, this kit provides a superior seal that prevents boost leaks and blown-off boots.

This intercooler pipe features an integrated threaded bung for the factory Intake Air Temperature (IAT) sensor and a CNC-machined flange with double O-rings for a precision fit. Finished in a durable Gloss Black powder coat, this kit is a 100% bolt-on solution that requires no tuning or additional modifications.

• Manufacturer Part Number: WCF100381-GB
• 3.5" diameter 14-gauge aluminum construction
• One-piece mandrel-bent design for improved flow
• CNC-machined flange with double O-ring seals
• Black anodized billet aluminum adapter
• Reinforced silicone boot and stainless steel T-bolt clamps
• Integrated threaded bung for OEM IAT sensor
• No tuning or ECM calibration required
• Includes new intercooler outlet retaining clip and hardware

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).

Fits select 2006-2010 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 models (6.6L LBZ/LMM Duramax).

This Wehrli Custom Fab 3.5" High Flow Passenger (Cold) Side Intercooler Pipe replaces the failure-prone factory plastic component with a heavy-duty, 14-gauge fabricated aluminum upgrade. Designed for improved airflow between the turbo and engine, this pipe increases throttle response and turbo spool-up while eliminating the common boost leaks associated with factory components. The larger diameter and smooth bends ensure maximum efficiency for hard-working trucks and high-performance applications alike.

Construction features a CNC machined flange with double O-ring seals to provide a superior sealing surface compared to OE designs. It includes an upgraded silicone hump boot and stainless steel T-bolt clamps specifically engineered to withstand higher boost pressures without blowing off. This bolt-on kit is compatible with stock trucks and requires no additional tuning or modifications for installation.

• 3.5 inch cold side intercooler pipe
• 14-gauge aluminum construction
• Gloss Black powder coat finish
• CNC machined flange with double O-ring seals
• High-quality HD silicone double hump boot
• Stainless steel T-bolt clamps
• New wire clip rings for slip flange connections
• Manufacturer Part Number: WCF100367-GB
• Made in the USA

Fits 2020-2025 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD (6.6L).

The Wehrli Custom Fabrication 3-inch High Flow Driver Side Intercooler Pipe (Hot Side) is engineered to optimize airflow and increase reliability on the L5P Duramax platform. This upgrade replaces the restrictive factory two-piece 2.5-inch intercooler pipe with a high-flow, one-piece 3-inch mandrel-bent pipe. By increasing the diameter and smoothing the air path, you reduce turbulence and improve efficiency between the turbocharger and the intercooler.

Built for durability, this kit includes upgraded heavy-duty silicone boots designed to withstand higher boost pressures and operating temperatures than factory components. These boots are secured with stainless steel T-bolt clamps to eliminate the common issue of blown-off factory boots under load. The pipe features a custom Gloss White single-stage powder coating for a professional look and corrosion resistance. This is a direct bolt-on component that requires no ECM tuning or additional modifications.

• 3-inch high-flow mandrel-bent hot side intercooler pipe
• Heavy-duty silicone boots for high-temp/high-pressure reliability
• Stainless steel T-bolt clamps included
• Gloss White powder coat finish
• Direct bolt-on installation with no tuning required
• Manufacturer Part Number: WCF100365-GW

Fits select 2020-2025 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD models equipped with the 6.6L L5P Duramax diesel engine.

The Wehrli Custom Fabrication 3-inch High Flow Driver Side Intercooler Pipe (Hot Side) is engineered to solve the restrictions found in the factory plumbing. This kit replaces the OEM two-piece 2.5-inch diameter pipe with a high-flow, one-piece 3-inch mandrel-bent tube. By increasing the diameter and streamlining the air path, this upgrade improves turbo response and efficiency.

Built for long-term reliability under high boost pressures, this kit includes upgraded heavy-duty silicone boots and stainless steel T-bolt clamps. These components are designed to withstand significantly higher temperatures and pressures than factory equipment, eliminating common failure points like blown boots. This is a direct bolt-on component that requires no aftermarket tuning or additional vehicle modifications for installation.

• 3-inch mandrel-bent high-flow one-piece pipe
• Premium Gloss Black single-stage powder coat finish
• Heavy-duty silicone boots for high-pressure applications
• Stainless steel T-bolt clamps included
• Direct replacement for restrictive 2.5-inch factory piping
• No tuning required for operation
• Manufacturer Part Number: WCF100365-GB

Fits select 2001-2016 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD (6.6L Duramax).

Upgrade your Duramax exhaust system with WCFab high-flow billet steel manifolds. Designed to replace restrictive factory cast units, these manifolds are CNC machined from billet steel and fully TIG-welded for superior strength under high exhaust gas temperatures (EGTs). Each manifold is exhaust port gasket matched and features an internally divided design to optimize gas flow for both OEM and ported cylinder heads.

The kit includes premium ARP 12-point fasteners for secure mounting and is finished in a high-temp Black Ceramic Coat rated for 2000°F. Integrated 1/8 NPT ports on both the driver and passenger side manifolds allow for the direct installation of EGT or drive pressure sensors. These manifolds are compatible with OEM-style up pipes and are engineered to pair with WCFab 2-inch Stainless High-Flow Up Pipes for maximum performance.

• CNC machined billet steel construction with full TIG welding
• Black Ceramic Coat finish rated for 2000°F
• Internally divided for optimized exhaust flow
• Dual 1/8 NPT ports for sensor integration (includes optional plugs)
• Includes ARP 12PT fasteners, washers, and assembly lube
• Includes manifold-to-head and manifold-to-up-pipe gaskets
• Manufacturer Part Number: WCF100363

Note: Up-pipe fastener kit WCF100240 is sold separately.

Fits 2011-2016 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD (6.6L).

The Wehrli Custom Fabrication (WCFab) 3" High Flow Driver Side Intercooler Pipe is a performance upgrade for the LML Duramax, replacing the restrictive factory two-piece 2.5" pipe with a one-piece 3" mandrel-bent design. This larger diameter increases airflow efficiency between the turbocharger and intercooler, supporting both factory and drop-in style turbochargers.

Designed for reliability under heavy load and high boost, this kit replaces prone-to-fail factory boots with heavy-duty silicone boots and stainless steel T-bolt clamps. The pipe features a durable, custom two-stage powder coating in WCFab Red to enhance engine bay aesthetics while providing superior corrosion resistance.

• 3" One-piece mandrel-bent high-flow intercooler pipe
• Replaces factory 2.5" two-piece restrictive piping
• Custom two-stage powder coating (WCFab Red)
• High-temperature, high-pressure silicone boots
• Stainless steel T-bolt clamps included
• Compatible with factory or drop-in turbochargers
• Manufacturer Part Number: WCF100353-RED

Fits select 2011-2016 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD (6.6L LML Duramax).

Replace the restrictive factory two-piece 2.5-inch driver side intercooler pipe with this high-flow one-piece 3-inch upgrade from Wehrli Custom Fabrication. Designed specifically for the 6.6L LML Duramax, this hot side pipe eliminates the common failure points of the OEM components, providing a direct-fit solution that handles increased boost pressures and higher under-hood temperatures without failing or blowing out boots.

• 3" High-flow one-piece driver side intercooler pipe
• Heavy-duty silicone boots designed for high pressure and temperature resistance
• Stainless steel T-bolt clamps for a leak-free seal
• Custom two-stage WCFab Grey powder coat finish
• Compatible with factory or drop-in style turbochargers
• Manufacturer Part Number: WCF100353-GRY

Fits 2011-2016 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD (6.6L LML Duramax).

Upgrade your LML’s charging system with the Wehrli 3" High Flow Driver Side Intercooler Pipe. This one-piece mandrel-bent pipe replaces the restrictive factory two-piece 2.5" assembly, providing a smoother, high-volume path for pressurized air. By eliminating the factory failure points and increasing the diameter, this "hot side" pipe improves turbo response and overall system reliability under load.

Engineered for durability, this kit includes upgraded silicone boots designed to withstand significantly higher boost pressures and temperatures than stock rubber, effectively preventing the common issue of blown boots. The assembly is finished in a durable Gloss Black powder coat and is fully compatible with the factory turbocharger or any aftermarket "drop-in" style turbo.

• Replaces factory 2.5" two-piece pipe with a high-flow 3" one-piece design
• Includes heavy-duty silicone boots for high-temperature and high-pressure resistance
• Secure mounting with included stainless steel T-bolt clamps
• Custom Gloss Black single-stage powder-coated finish
• Direct fit for OEM and drop-in style turbochargers
• Manufacturer Part Number: WCF100353-GB

Fits 2011-2016 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD models equipped with the 6.6L LML Duramax diesel engine.

The Wehrli Custom Fabrication 3" High Flow Driver Side Intercooler Pipe is engineered to replace the restrictive factory two-piece 2.5" assembly. By upgrading to a larger one-piece 3" mandrel-bent pipe, this kit improves airflow and reduces turbulence between the turbocharger and the intercooler. This "Hot Side" pipe is designed for maximum reliability, featuring heavy-duty silicone boots and stainless steel T-bolt clamps that are built to withstand higher boost pressures and temperatures than OE components, effectively eliminating the common issue of blown factory boots.

• One-piece 3" mandrel-bent high-flow intercooler pipe
• Custom Bengal Blue single-stage powder coat finish
• Upgraded heavy-duty silicone boots for high-pressure/high-temp resistance
• Stainless steel T-bolt clamps included
• Compatible with factory or drop-in style turbochargers
• MPN: WCF100353-BB

Fits select 2004-2010 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD (6.6L LLY/LBZ/LMM Duramax).

Upgrade your Duramax's cooling system with the WCFab One-Piece High-Flow 3-inch Driver Side Intercooler Pipe. This component is engineered to replace the restrictive 2.5-inch OEM hot side pipe, significantly increasing airflow for improved turbocharger efficiency and performance. While the factory pipe utilizes a reverse-style bead roll at the turbo—a design prone to blowing off under increased boost—this Wehrli Custom Fabrication pipe uses a superior configuration with high-pressure rated straight boots for maximum reliability.

Each pipe is finished in a durable WCFab Red two-stage powder coating for long-lasting corrosion resistance and a custom under-hood look. The kit is a direct bolt-on solution that eliminates the failure-prone angled boots of the factory setup, ensuring your charge air system remains sealed even under heavy load.

• Manufacturer Part Number: WCF100352-RED
• Pipe Diameter: 3-inch (upgraded from 2.5-inch OEM)
• Construction: One-piece high-flow mandrel-bent tubing
• Finish: Custom Two-Stage Powder Coating (WCFab Red)
• Boots: High-pressure rated silicone straight boots
• Hardware: Heavy-duty T-bolt clamps included
• Compatibility: Replaces factory hot side pipe on LLY, LBZ, and LMM engines

Fits select 2004-2010 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD (6.6L LLY/LBZ/LMM Duramax).

Upgrade your charging system with the Wehrli Custom Fabrication (WCFab) 3" High Flow Driver Side Intercooler Pipe. This one-piece mandrel-bent pipe replaces the restrictive 2.5" OEM hot-side plumbing with a full 3" diameter for improved airflow and reliability. The factory pipe utilizes a reverse-style bead roll design at the turbo connection that is prone to blowing off under higher-than-stock boost levels; WCFab eliminates this failure point by using high-pressure rated straight silicone boots and heavy-duty clamps.

Finished in a durable single-stage Gloss Black powder coating, this kit provides a professional look while ensuring your LLY, LBZ, or LMM engine maintains consistent boost pressure during heavy towing or performance driving.

• 3" mandrel-bent high-flow construction
• Replaces restrictive 2.5" OEM driver-side (hot side) pipe
• Single-stage Gloss Black powder coat finish
• High-pressure rated straight silicone boots (no angled boots)
• Heavy-duty T-bolt clamps included
• Manufacturer Part Number: WCF100352-GB