Guys, just for future reference, there is a website that I found when I was dealing with switching rim size and tire sizes.
Check out the
Tire & Wheel Calculator
As far as the 2 tires in question, @ 60 mph (96.54 kph) according to your speedometer will actually be 61.42 (98.83 kph)
If you don't like my answer, do the research yourself. This information is as accurate as I could find on the net (Verified by my mechanic also).