Is there an advantage over Mild Steel vs. Stainless Headers?
409 Steel is a less expensive header material, but when uncoated can still exhibit corrosion. 304 is a high quality stainless steel. However, stainless steel may create hotter underhood temperatures, which is one of the bigger concerns with racing Vipers (as well as driving them daily). Standing next to a Viper with stainless headers compared to one with alumanized 409 headers, you can feel the temperature difference between them. Another advantage of running coated alumanized mild steel headers is that stainless is not as flexible. Stainless steel is more temperature-sensitive to embrittlement than mild steel.