I run stock wheels and 315 70 17 tires and I rub pretty hard on the rear end, but I havnt gotten any spacers for it et since I just noticed
Stock wheels are 6.5" I would recommend 1.5 spacers it may not rub without them now but it will when you flex
Measure back spacing. Put a straight edge across back side of rim out where the tire mounts on and measure to where it bolts on to hub face.
Is your rear sway bar as close as mine?