I would go with at least 2.25" exhaust, unless the 2" is mandrel bent all the way back. If you go with 2" non mandrel bent like most exhaust shops make, the kinks and bends are going to restrict to way less than 2", probably closer to 1.75" or worse. This is why I chose to stay as big as I could at the time on mine and went with 2.25". I would've gone 2.5 as this is the size of my collector on the header, but the exhaust came before the header did so I stuck with it.