at the stock non-turbo headers. They used some monster gauge pipe for those things so I am left to assume that more material = better. 18-gauge is just so thin. You mentioned before that this stuff welds nicely - I laid a nice bead around a pipe just for kicks and stainless produces a significantly better weld than mild steel. If I could get some 348SS spool wire for my welder, I would almost be tempted to MIG it it looks so nice. :)