Ok, I went to
Tire Rack - Your performance experts for tires and wheels and did a little research.
First, there is no 225 70R16 in a General Grabber AT2. :huh:
There is a 215 70R16 with a 28.1 inch inflated diameter and a 235 70R16 with a 29.2 inch inflated diameter.
By comparason, my stock Yokohama GeolanderH/T 695A 225 55R17 on my '09 XT have an inflated diameter of 26.8 inches.
This would give you 1.3" total height difference on the "215" series and 2.4" total difference compared with the 235 series.
-or-
If you wanted to take a tape measure and measure out either 14 1/4 inches from the center of the hub or 14 3/4 inches from the center of the hub, you can find if there are any areas which might rub (or get really close) as far as overall height.
If you are concerned about width, then you can use the reference tool on Tire Rack's web site and measure that compared to your stock tires as well.