Actually, this will probbly over compensate that difference. Your tire size is going up 10-11%, while your speedo is only about 5% off. When reading 65, you will probably be doing 68 or so with the bigger tires. This will depend on the accuracy of the sizes, the wear on the old tires, etc. Still, with your current tires and the new ones, the difference is pretty minute, and not really worth changing the speedo gear or making a fuss over IMO.
If you find it is a little faster than the speedo after the swap, just keep that in mind at higher speeds.

My rpms are at 2200 at 70 and about 1900-2000 60-65. Im running 3.07's and have 31's.

jmm0122, I looked at your numbers, are you getting your speed off the the speedometer? Looks to me like you should be turning a lot lower rpms, like about 300 less. Check out this chart.

http://www.grimmjeeper.com/gears.html

Yeah. The speedo is off by a few miles per hour so that might be where the error is. Who knows.

31s and stock gears on a 5 sp and I run 1800 rpm at 55

I did a similar thing. My speedo was off (high) about 4 mph at 60 (according to my GPS) with stock tires (225/70-16). When I put my 225/75-16 AT's on it corrected the speedo to about 1.5 mph fast at 60. The tires are just about an inch difference in diameter. I've got 3.55 gears and the AW4 and I run just under 2K at 60 mph.

I've heard the most fuel efficient rpm range is about 2200-2500 if I'm not mistaken.

lol ya i dont plan on changing anything, i have never owned a vehicle with an accurate speedo lol my other rig is a ramcharger, and if it reads 65 im going about 74 lol, 33 inch tires and its factory tires are 225's for some reason. even my ninja is off, it reads 75 and im goin 71 lol im used to it.

I've heard the most fuel efficient rpm range is about 2200-2500 if I'm not mistaken.[/QUOTE]
i know running 65 i get around 22 mpg, and 75 i get right at 20 on average, with stock tires