GMC Sierra Twin Turbo Kit - Wehrli - S400/Stock - Illusion Blueberry - 01-04. A compound setup for 2001-2004 Duramax LB7 that pairs an S400 atmosphere turbo with the stock IHI to add power while keeping familiar spool behavior. Turbochargers are sold separately.

Built for daily drivers, work trucks, and tow rigs, this made-in-USA kit is engineered for stronger top end, improved fuel efficiency, and confident EGT control with appropriate supporting mods. Finished in Illusion Blueberry, it includes a 4 in ceramic-coated downpipe, 5 in intake with dry filter and pre-filter, stainless oil feed/return lines, S400 pedestal, one-piece Y-bridge, cold-side tubing, clamps, heat wrap, and a coolant overflow tank with low-coolant sensor.

Features

• 2001-2004 Duramax LB7 fitment; S400 over stock IHI compound layout
• Recommended combos: S475/stock ~750 RWHP; S480/stock 800+; S480/64 mm 900+ with supporting mods
• 4 in ceramic-coated downpipe; 5 in intake with dry filter and pre-filter
• Stainless oil lines; S400 pedestal with built-in oil return
• 3 in one-piece Y-bridge; 3.5 in cold-side charge pipe; 3 in cold-side intercooler pipe; 3.5 in turbo inlet horn
• Coolant overflow tank with sensor; silicone boots; T-bolt/V-band clamps; heat wrap
• Requires passenger-side battery relocation; hot/driver-side intercooler pipe sold separately (WCF100349); not compatible with Banks intercoolers (contact us for options; additional cost/lead time)

Have questions or planning an install? Call our Austin, Texas or Los Angeles, California area teams. We offer installation and customization at both locations: 512-982-9393 (TX) or 562-981-6800 (CA).

Thinking about purchasing multiple items? Contact us for shipping discounts. We install on premises at both locations.

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov