The Duramax engines were built with great potential at the world’s fingertips. Part of that potential is restricted by the factory up-pipe that has small diameters and a large indent which inhibits smooth & steady airflow. GDP up-pipes have a larger piping diameter to support more air volume, plus no more indent that disrupts smooth consistent air flow. The result is cooler engine temps, unrestricted power potential, and a healthier running truck.
