Never did recalibrate the speedo. I'm not going as fast as it says (I hope). Also went to a 200 Avon Cobra rear tire on a 5.5" dish "A" wheel, so it's taller just to screw with the speedo a little more.
Did the mods one at a time. Biggest difference was the pipe - made the whole bike. The 26t really does help with that "gut" feel, ready to rev now. Really wails at high speeds, not sure how many revs higher at different speeds. Seriously, if they made a 25t I would do that. But then I'm an ex drag racer and this is a toy to terrorize the neighborhood on, not a touring machine. Spends much of it's life going 0 - 80 and not so much time on the interstate.