DC Sports header systems for the 2003-2006 Nissan 350z are dyno tested to outperform all comparable header systems on the market. Extensive research and development goes into each system to ensure the best performance for your 2003-2006 Nissan 350Z. DC Sports header systems are precision bent on CNC mandrel benders using data acquired from non-contact digitizing scanner. The flanges are CNC machined and the flange-mating surface is machine ground to ensure a leak-free seal. A robotic welder is used to attach the flange to the header pipes. This state-of-the-art manufacturing process ensures superior quality and a perfect fit with every header system.