If yoy don't want to alter the opening or raise the rear end you'll be running 28". I know there are guys running taller but either the front of the opening is moved forward, the axle is moved back or the rear is pretty high. We just went through this with Dizusters Duster. He wants it to sit low. I believe we came up with 10.5X28W or 11.0X28 slicks, 13.50X28 ET Streets.
Doug