Is WCFab Grey a darker or lighter shade?

WCFab Grey is a medium-tone grey that blends well with factory engine bay colors. It gives the components a clean, professional appearance without drawing too much attention.

Does this include everything I need for installation?

Yes. Silicone boots, stainless steel T-bolt clamps, O-rings, intercooler outlet clip, and all mounting hardware are included. You just need standard hand tools and engine bay access.

Can I install only some of the components and save the rest for later?

You can install the intake system, intercooler pipes, Y-bridge, and down pipe in separate sessions if needed. Each section connects to the adjacent factory or Wehrli components independently.

Is this kit CARB approved?

No. This kit is not CARB approved. It is intended for off-road or competition use in states that follow CARB regulations. Check your local emissions laws before purchasing.

Specifications

Brand: Wehrli
Part #: WCF100503-GRY
UPC: WCF100503-GRY

Wehrli 06-07 Chevrolet 6.6L Duramax LBZ Stage 3 High Flow Bundle Kit - WCFab Grey

Name: Wehrli 06-07 Chevrolet 6.6L Duramax LBZ Stage 3 High Flow Bundle Kit - WCFab Grey
Brand: Wehrli
SKU: wehrli-wehrli-06-07-chevrolet-6-6l-duramax-lbz-stage-3-high-flow-bundle-kit-wcfa-t14-647177
Price: 2928.64 USD
Availability: BackOrder

$2928.64

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Fits 2006-2007 Chevy Silverado/GMC Sierra 2500 HD and 3500 with 6.6L Duramax LBZ. Complete Stage 3 bundle with intake, intercooler pipes, Y-bridge, and down pipe in WCFab Grey.

Key Features

Fits 2006-2007 Chevrolet Silverado 2500 HD/3500 and GMC Sierra 2500 HD/3500 with 6.6L Duramax LBZ.
Complete Stage 3 bundle: intake system, intercooler pipes, Y-bridge, and 3 in. stainless steel down pipe.
4 in. aluminum intake with air box, dry filter, pre-filter, and 4.8 in. intake horn (20% more airflow).
3 in. hot-side and 3.5 in. cold-side intercooler pipes (cold side flows 47% better than stock).
3 in. bolt-together Y-bridge flows 36% better than stock with CNC billet flanges.
3 in. stainless steel turbo down pipe with heat wrap.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Will this fit your vehicle?

Advanced difficulty to install

Full-day bolt-on project covering intake, intercooler piping, Y-bridge, and down pipe, requiring mechanical experience with the Duramax LBZ engine bay.

About this part

Product Details

Wehrli Stage 3 High Flow Bundle Kit for 2006-2007 Duramax LBZ - WCFab Grey

WCFab Grey is the understated option in the Wehrli color lineup. It gives your LBZ engine bay a clean, factory-adjacent look while hiding the fact that the entire intake and intercooler tract has been rebuilt from the ground up. This Stage 3 kit covers intake, intercooler piping, Y-bridge, and turbo down pipe.

Air intake: Cold air enters through the inner fender via a 4 in. aluminum pipe into an enclosed air box with a dry filter and Outerwears hydrophobic pre-filter. The 4.8 in. turbo intake horn is sized for 20% more airflow than stock. All intake piping is 14-gauge aluminum with mandrel bends that keep air moving smoothly and add a more pronounced turbo whistle under throttle.

Intercooler piping: Factory 2.5 in. hot-side and plastic cold-side pipes get swapped for Wehrli's 3 in. driver-side and 3.5 in. passenger-side aluminum pipes. The cold side flows 47% better than the stock assembly. CNC machined flanges with double O-ring seals and silicone hump boots rated for higher boost pressures replace the leak-prone factory connections.

Y-bridge: The 3 in. bolt-together design replaces the slip-fit factory unit and flows 36% better. CNC billet flanges, a full 3 in. tract to the engine, and retained factory grid heater and EGR connections make this a true bolt-on replacement.

Down pipe: A 3 in. stainless steel pipe with heat wrap replaces the factory exhaust section after the turbocharger, removing the last restriction in the airflow path.

All installation hardware, silicone boots, T-bolt clamps, and O-rings are included. Made in the USA. WCFab Grey is one of the more affordable finish options in the Wehrli lineup.