2001-2004 LB7 Duramax Stage 3 High Flow Intake Bundle Kit

The full LB7 airflow package

Stage 3 rolls Wehrli's Stage 1 high-flow bundle, Stage 2 intake and 3 in. downpipe into one kit. Factory Y-bridge and both intercooler pipes give way to 3 in. mandrel-bent aluminum feeding Wehrli's TIG-welded billet Y-bridge, for a full 3 in. path from turbo to engine.

Up front, a 4 in. aluminum intake and 10 ga aluminum air box pull cooler air through the inner fender, and a 4 in. turbo inlet horn opens the path into the turbo. The straighter 3 in. downpipe replaces the crimped factory pipe and helps cut underhood heat.

Wehrli says the result is quicker throttle response, faster spool and lower exhaust temperatures.

Who it's for

LB7 owners on a stock or drop-in IHI-style turbo who want the whole intake and downpipe upgrade at once.

Key specs (per Wehrli)

What's included

• 3 in. billet Y-bridge
• 3 in. hot and cold side intercooler pipes
• 4 in. intake pipe, air box with lid, dry filter and pre-filter
• 4 in. intake horn
• 3 in. downpipe
• FPRV block-off kit for Y-bridge clearance
• Silicone boots, stainless T-bolt clamps, O-ring seal, hardware and gaskets; powder-coated finish

Fitment notes

• Fits 2001-2004 Chevrolet Silverado / GMC Sierra 2500 HD and 3500 with the 6.6L LB7 Duramax.
• Not recommended with S300 or S400 turbos; see Wehrli single turbo kits WCF100478 / WCF100489.
• On 2001 trucks the MAP sensor sits on the intake runner: move it to the MAP port built into the new bridge and plug the old port (plug not included), or use a 2002-2004 runner.
• California: Wehrli does not ship this part to California.

Professional install available at Powertech Diesel, Idaho Falls — call 208-542-7793.