The reason why you would switch tunes is if your custom tune didnt take into account the CAI. if you have a CAI and no custom tunes you should use the 87 Tow tune because it runs a little richer(canceling out the lean effect of the CAI a little). if you told PHP about the CAI then you have nothing to worry about once you get your CS, Bill should have covered whatever issues the CAI would have in the tune. now if you didnt tell them about your CAI then you need to talk to them ASAP so that they can take it into account for your custom tunes. Hope this helps!
