Wehrli 01-04 Duramax LB7 Twin Turbo Kit S400/Stock - Gun Metal

If you're looking to significantly boost the performance of your 2001-2004 Duramax LB7 Silverado or Sierra, this Wehrli twin turbo kit is a solid choice. It's designed to work with either a stock IHI turbo or an S400 series charger, giving you options for how much power you want to make. This kit is capable of supporting up to 1000 rear-wheel horsepower, depending on your turbo and fuel system setup, making it suitable for daily drivers, tow rigs, and performance builds that need more grunt.

Wehrli Custom Fab put this kit together with everything you need for a comprehensive upgrade. You get a durable, custom gun metal powder coat finish that looks great and resists corrosion. The kit includes a 4-inch downpipe with a ceramic coating to help manage heat, a 3-inch one-piece Y-bridge with heavy-duty bead rolls for a strong seal, and a 3.5-inch cold side charge pipe. Stainless steel oil feed and drain lines are included, along with a coolant overflow tank, silicone boots, and all the necessary clamps. The atmosphere turbo pedestal features a built-in oil return fitting, simplifying the plumbing.

This kit offers improved horsepower and better exhaust gas temperature (EGT) control while maintaining stock-like turbo spool characteristics, especially when paired with an S475 turbo. For those seeking more top-end power, an S480 turbo is also an option. Supporting modifications, like a built Allison transmission, are recommended for higher horsepower applications. This kit is made in the USA and comes with a dry air filter featuring an Outerwears pre-filter cover.