Just some 35x12.50x20 I'm gonna get them on some large wheels so they will have a lower sidewall for handleing since I have no ab conrol now I can't lean into the turns cause I can't hold my balance to good.

I was told by the shop that did the modifications that they would fit and the most I would have to do would be trim the plastic on the bottom of the front bumper.

The tires on it now are 285/75/16(32.8x11.22)

For those of you who don't already know, it's an 03' 2500HD 2wd but has a 4" bodylift so they could cut the driver floor out and lower it. Hence the bottom of the doors being extended.