I'm going to convert my 08 V6 to dual exhaust soon and I'm trying to figure out if I want to just go with a GT exhaust or if I should just get an aftermarket one. I want something that will give me good power gains and a louder, lower sound but I don't want anything TOO pricey.
You're not going to get much of a power gain from exhaust. A few hp but that's about it.
I'd say go to a custom exhaust shop, have them custom fab you an H pipe and pick up a set of GT takeoff mufflers ($50 or so). Cheapest route and sounds great for what it is
No you don't need a tune for it, and if you go that custom route be aware all exhaust shops use cheap Chinese piping. You must ask for stainless steal or your custom exhaust will rot out after a couple years. Just be sure you get an estimate first you may be surprised it wont be as cheap as you think.