With headers you're definitely going to be much louder than stock.
I have 12" res with stock cats and the note has settled down after close to 25k miles so far. Maybe I just got used to it but it's not as loud as I remember it being the first time I got it. It's still a really nice tone and the so called drone is not even apparent anymore.
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SOLD 12/30/2011 2010 370Z Coupe Monterey Blue 6MT/Touring/Sport/Nav
F.I. CBE CF w/ 12" Res | V1 | SecondSkin | Stillen G3 | EVO-R CF B-Pillars | Volk GT-S Ti Gunmetal 19x9.5 +30 F, 19x10.5 +8 R | Swift Spec-R Springs
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