it cracked on the driver side between where the 2 tubes are welded together for cyl 1 and 2.. DC warranty will cover it if you are persistant with them being it usually cracks after 3 yrs but you have to send it to them to be inspected and they make you pay the shipping both ways.
the way I could tell it was cracked was the smell of exhaust under the hood. then you look at the header where the 2 peices bolt together and there it is a nice crack right next to the weld.
the header tube is what actually cracks not the weld.