The 215 75 15 will fit just fine on the front, it's the same height as a 225 70 15 The 235 75 15 will fit fine on the rear, but may be a little too tall for you liking. Personally if I had to go with a 75 series, I would go 215 75 15 all the way around. You don't really have much to work with in a 75 series tire without getting into height clearance issues when going to larger section widths. Hope this helps, good luck
Tom
