All traditional ARH features come standard including 3/8" thick flanges with hand ported inlets, U.S. made 304 S/S throughout, merge collectors with scavenger spikes, 200 cell metallic substrate cats, and your choice of 1-3/4"or 1-7/8" primary headers. Expect outstanding performance gains throughout the rpm range. For peak performance we recommend street and/or dyno tuning.