True, if your speedo is reading 60, your really doing 61.54 mph. Shouldn't be a problem especially if you know it is actually going faster than it is reading. At 35, its only 1 mph faster, and at 75 its only 2.06 faster. I don't know what you could do about recalibrating, I think there is a different gear for the speedo where it connects to the transmission, but wouldn't have a clue which size. I would just roll with it and know your going 1 to 2 mph faster than what your reading. Easy enough.
I think a speedo gear change would throw it off even worse. 1-2mph error on a factory speedo is good. I've found them to be as much as 5mph fast(GPS confirmed) with stock wheels and tires.
