I think the bottom line is that you're going to have to answer this for yourself. Remove both rear wheels, using a carpenters square, measure (BOTH SIDES) how much room you have to work with. The rim you've chosen has 4.25 front space, add tire width + about 5/8" (15 millimeters) for sidewall flex. The 275/60/15 tires you inquired about are 10.8 inches wide. So if my calculations are correct, you'll need 6.25 inches from the face of your brake drums to the wheel well lip for that tire to safely fit. If my numbers are jacked up, someone will soon chime in...