The CMI 454/502 E-Top Header Kit is a a true plug and play system. There is no need to purchase additional custom pipes. These are a direct replacement for your stock 454/502 engine. CMI headers offer more water jacketed protection than your stock exhaust can provide. CMI uses the same high quality semi-automated process on these headers as with the entire product line. These headers are fully post annealed to reduce stresses built up in the header during the manufacturing process. Best of all, 454/502 E-Top headers are made to last, they are mandrel bent and formed from hight quality 316L grade material. There are no parts to crack, all CMI collectors are forged from American made Stainless Steel.