I'm currently running 315/70/17's on stock steelies. The spare does rub on the rear bumper when the door is shut which requires me to put more effort into shutting it all the way. Deflating the tire a little did help. The only issue now, is that I can't open the rear hatch window all the way.
I know others have made a spacer to push the wheel/tire farther off the door.
I'm running 305/65 17's and I added a SpiderTrax 1.25" wheel spacer to the spare tire carrier. You will have to bend the support down just a little for it to fit.