I have BF Goodrich 235-70/15s on my 55 1st suburban, and don't have any trouble with the tires hitting anything.
The fronts did just touch on the inside behind the axle, but when I converted to disk brakes they moved outside just enough to stop that.
I think these are only 28.5 tall, but the 8-inch width isn't a problem, so you might be able to use the same width with a taller aspect ratio and be okay?
Hope this helps...
