Stock-ish 5.7 Build...2.5" or 3" Exhaust?

I'm putting a 2013 5.7 (395HP according to literature) in my 68. I have decided that I'm not going to mess with it internally at this point, though I will likely play with the tune some. I am trying to decide on exhaust size, and wondering if a fairly free flowing 2.5" system is sufficient, or is it worth stepping up to 3"?

Thanks!