These shorty headers are the perfect combination of quality and value. Mandrel bent tubing provide consistent tubing diameter for smooth flow and increased exhaust velocity. Heavy duty 16 gauge tubing provides increased strength and durability. 1-5/8 in. primary tube diameter increases exhaust flow for increased performance and improves throttle response. The OE style 2-1/2 inch ball and socket collector connects to factory exhaust head pipe. They accommodate all factory OE components and include a premium aluminum header gasket. Headers are a must in you are using cold air intake, cat-back exhaust, or tuner.