Do I need a tune to run this kit?

No. The Stage 2 High Flow Bundle bolts onto a stock truck and works with the factory ECM calibration. No tuning is required, though some owners choose to add a tune separately for further gains.

What is the difference between Stage 2 and Stage 3?

Stage 2 includes the intake system, intercooler pipes, and Y-bridge. Stage 3 adds a 3 in. stainless steel turbo down pipe with heat wrap to the Stage 2 package for additional exhaust flow improvement after the turbocharger.

Will this work with an aftermarket intercooler?

Wehrli notes that CSF aftermarket intercoolers require modification or grinding of the intercooler outlet lip for installation. Factory intercoolers work without modification.

Is this kit CARB approved for use in California?

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 #: WCF100437-GW
UPC: WCF100437-GW

Wehrli 06-07 Chevrolet 6.6L Duramax LBZ Stage 2 High Flow Bundle Kit - Gloss White

Name: Wehrli 06-07 Chevrolet 6.6L Duramax LBZ Stage 2 High Flow Bundle Kit - Gloss White
Brand: Wehrli
SKU: wehrli-wehrli-06-07-chevrolet-6-6l-duramax-lbz-stage-2-high-flow-bundle-kit-glos-t14-647166
Price: 2703.68 USD
Availability: BackOrder

$2703.68

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 2 high flow intake, intercooler pipe, and Y-bridge bundle in Gloss White.

Key Features

Fits 2006-2007 Chevrolet Silverado 2500 HD/3500 and GMC Sierra 2500 HD/3500 with 6.6L Duramax LBZ.
4 in. aluminum intake pipe with air box enclosure, dry filter, and Outerwears hydrophobic pre-filter cover.
4.8 in. turbo intake horn flows 20% more air than stock according to Wehrli.
3 in. driver-side (hot) and 3.5 in. passenger-side (cold) intercooler pipes replace the restrictive factory units.
Passenger-side pipe flows 47% better than stock according to Wehrli.
3 in. two-piece bolt-together Y-bridge replaces the factory slip-fit design that is prone to failure under boost.

⚠️ 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

Multi-component bolt-on installation covering intake, intercooler piping, and Y-bridge, requiring several hours and familiarity with the Duramax LBZ engine bay layout.

About this part

Product Details

Wehrli Stage 2 High Flow Bundle Kit for 2006-2007 Duramax LBZ - Gloss White

Your LBZ Duramax has solid bones from the factory, but the plastic intake components and restrictive intercooler piping leave airflow on the table. This Wehrli Stage 2 High Flow Bundle replaces those weak points with a complete aluminum intake system, upgraded intercooler pipes, and a redesigned Y-bridge, all finished in Gloss White powder coat.

On the intake side, you get a 4 in. aluminum intake pipe, an air box enclosure with a dry filter assembly, and a hydrophobic Outerwears pre-filter cover. The 4.8 in. turbo intake horn is the largest available for this platform, flowing 20% more air than stock according to Wehrli. All piping is 14-gauge aluminum with smooth mandrel bends. The removable air box lid makes filter inspection and maintenance simple.

Between the turbo and engine, the kit replaces the factory 2.5 in. hot-side intercooler pipe and the leak-prone plastic cold-side pipe. The Wehrli 3 in. driver-side (hot) pipe and 3.5 in. passenger-side (cold) pipe are both 14-gauge aluminum with mandrel bends. The cold-side pipe flows 47% better than stock according to Wehrli, and the CNC machined flanges with double O-ring seals address the boost leak issues that plague the factory plastic and rubber connections.

The centerpiece is the 3 in. Y-bridge, replacing the factory slip-fit two-piece unit that is known for blowing apart under boost on hard-working trucks. Wehrli's bolt-together two-piece design with CNC machined billet flanges creates a secure sealing surface. The 3 in. upper and lower intercooler pipes complete a full 3 in. tract from intercooler to engine, incorporating the factory grid heater and EGR connections for emissions compliance.

Everything bolts onto a stock truck with no tuning required. Silicone boots, stainless steel T-bolt clamps, O-rings, and all installation hardware are in the box. Made in the USA.