This system produced gains of up to 18 HP and 25 lbs. x Ft. TQ., as measured on our in - house dyno. This system is constructed of 1 - 78 mandrel - bent 304 stainless steel tubing for maximum strength and durability. Factory style laser cut machined 304 stainless steel flanges are used used for a secure leak - free seal. 4 - to - 1 Mitered Merge collectors decrease turbulence and increases exhaust velocity. The result is increased horsepower, torque and improved throttle response. Utilizing factory style and flanges this system is designed to fit in the stock locations with no cutting or modifications required for a hassle - free installation. Utilizing state - of - the - art computer - aided design technology, this header is designed for custom, high tolerance factory fitment. 100 MIG - Welded for race - proven strength and durability.