The American Racing Headers are made with the highest quality T-304 Stainless Steel. They were designed to fit perfect and perform even better. These headers all come with 3/8" thick flanges, merge collectors with scavenger spikes and a direct bolt-in X Pipe with your choice of Heavy Duty High Flow 200 cell metallic substrate cats or in an Off Road version. If you have any questions regarding this product please feel free to give your Lethal Performance Sales Associate a call today!!