Which wheels do you have? According to the manual, they should be either 15" or 17" 2 peice wheels. Either way, modern tires will not work very well with them. I would suggest swapping out to a 16x7 modern single peice wheel with a 3.5" backspace, and use a 235/85/16 tire. That will be very close to the OE size in diameter and load rating.
