2.5 inch or 3 inch
Is all depends in what you want, my friend, if you want to squeze the most of your combo, go for the 3" if noise and comfty is an issue go for the 2.5" IMO the easyer to expell the burnt gasses the best for your engine performance, i know some people will say back preassure flabla blabla hell no, race cars do it with open headers and do it better think about it!