I installed the SS Autochromes about a week ago, used oem gaskets and have no leaks, I also reset the ecu and havent really driven it enough to tell if there is a difference (2002 w/34k)-I maybe drive 20 miles a week. I did alot of research b4 buying the headers. I went to 4wheel parts and looked at the jba's b4 buying and the quality of the welds turned me away from them.
Hopes this helps.