After repairing the stock drivers header, the next weak link is the cross over pipe. At high power levels they crack ALOT. I've seen them crack over and over again. The material is very thin and there are a lot of real bad gouges from poor tooling that GM used. The flares crack, too. Other than that they will work fine deep in the 9 second zone. If the $$ won't kill ya.......buy the TA headers. But even they will eventually crack. In a turbo environment there are two types of headers........ Ones that have cracked, and ones that will.