I was told one inch taller and one inch wider

 

You can put anything on there dude. Well, you can't put a 12" wide tire on the slim front stock wheels, but you can put it on the rears. And height won't matter with the rim, only with clearing the fenders. You could fit a good 27" combo on there easy. As far as the rims are concerned, only width matters for mounting purposes. I'd say 10" wide fronts will go just fine and anything made will fit on the rears. They are like an 8" wide rim. 12's would go nicely on there.

As far as clearing stuff, I don't know if a 12" wide rear will rub on the shocks or not with stock rims. I run 27" tires on mine and they work fine front and rear. The rear will rub the lower black fender a little, but other than making some noise sometimes, it doesn't hurt anything. Only rubs when your suspension compresses. Standing still, it doesn't touch.

 

I have seen 28x12x12's on them.