Rear Tire Sizes

I'm more interested in the height. If I'm not mistaken the 235 refers to the width. The 235's on it do not hit the springs because of the spacers I have in there. I'd like to go up to a 70 aspect ratio but I'm afraid the tire will hit the upper wheel well when I hit a bump. As it is the 235's are only about 1.8" from the springs but they've never hit yet.