The LLY Duramax has a very restricted charge air system from the factory. After realizing the potential power loss from the small diameter factory tubes, we increased the size of the tubing to 3'' which proved major power gains over the factory intercooler system. While dyno testing the HSP upgraded intercooler tubing, we saw incredible horsepower and torque gains from such an over-looked component. This Tube will flow 53% above what the factory unit is capable of. Power increases will fluctuate between models do to tuning calibrations, turbo options, and aftermarket fuel systems. One thing to be sure of though, you will only be able to move as much air as your intercooler system will flow. So, be sure to use the HSP upgraded charge tubes to maximize the potential of your truck. This kit comes with a 3" boot to pair with your already purchased LLY factory replacement bridge.