You can look on the YEAR ONE site to look at the chart to see what speedo gear is needed. Its the tire OD and gear in the rear end that matters not tire ID.
Couldn't find that chart but I did find a tire size calculator which confirms that my way of thinking is correct.
180-75-13 original to 225-75-14 should make the speedometer read slow by about 10 percent. I.E. reading 60 mph should be actual speed of 66 mph.
I think this makes it obvious I have the wrong gear in the tranny. Anybody know which gear I would need and where to get one?