The WCFab Stage 1 upgrade for the 2011-2016 LML 6.6L Duramax Diesel Chevy Silverado or GMC Sierra 2500 / 3500 HD truck improves airflow between turbo and engine for improved efficiency throttle response and spool-up. Eliminates weak points in OEM design that lead to boost leaks or complete failures in hard-working and high performance trucks. The High Flow Driver (Hot) Side Intercooler Pipe replaces the OEM two-piece 2.5” pipe with a larger 3″ tube. The High Flow Passenger (Cold) Side Intercooler Pipe replaces the factory plastic two-piece pipe with a high flow 14 ga. aluminum one-piece 3.5″ tube. Includes upgraded silicone boots to withstand higher boost pressures than OEM components to increase reliability and eliminate blown couplers and horsepower-robbing boost leaks. This LML Y-Bridge Kit replaces the OEM upper intake manifold supplying air to the engine intake runners and cylinder heads. The OEM Y-bridge for these trucks is a restrictive part that creates a bottle neck in the air intake tract and limits engine performance potential. This kit includes a high flow precision CNC machined cast aluminum intake bridge (40% more airflow than stock) together with a unique 20% larger than stock 3″ fabricated aluminum upper crossover intercooler pipe that allows you to take full advantage of the larger inlet diameter Y-Bridge. The combination improves total air flow by 33% over the stock setup providing maximum volume for the available space. This means you get the most out of your engine in terms of performance and efficiency. Incorporates factory intake air heater grid for superior cold weather performance. Billet resonator plate eliminates the stock plastic resonator for improved engine appearance and more aggressive turbo and engine sound. Compatible with OEM throttle valve and EGR controls. Finished in your choice of custom powder colors. This product is compatible with stock trucks requiring no additional modifications upgrades or tuning for install.