I have a '96 s-10, with the factory tires on it (205/75/15). I want to replace them with larger tires (and a more aggressive tread

), but I'm not sure how big I can go without scrubbing. I tried on a friend's 225/75/15's and they worked fine, but I was told that I could probably go to a 235/60 or 235/65. Could anyone give me some help? Thanks.
c.roberts