Like its been said, stock headers are good into the 10s. I went 10.97 on them. If, and I say this from experience, you can keep them from cracking. My stock drivers side header had been welded up four times, and the passengers side once. Last summer I found them both cracked. DS was cracked all the way around the collector, and the PS header was blown out between #3 and #5 tubes, in a nice rectangular fashion.
I went to TA stock replacements. Excellent quality, fit perfect. No issues. The turbo flange was a bit of trouble though, as it expands slightly right under the flange. No big deal, just use a wrench to tighten the nuts. Other than that, they're perfect.
Sound has changed too with the new cam, sounds throatier at idle and off idle. Also the 1.5" crossover improved spoolup over the 2.5" Kirban one I had previously.