My best suggestion is to measure the rear yourself.
Take off the wheel and place a jackstand on the axle.
Run a plumb line from the spring, the inner lip of the wheel well, and one off the brake drum face keeping the plumbs in line. Take your measurements and you'll know exactly what you're dealing with. I'd recommend measuring both sides if you're going to put the largests tires possible, just to be sure there is no variation in the sides.