I have Black Rock 997's 15 inch with 4.75" backspacing. Currently I have BFG AT's that are 33x10.5x15. I'm a long way off from needing tires but was wondering if I could pull off 33x12.5x15s when I'm ready for new tires. Would this be possible or do I need to buy new rims too? The rims are less than 10,000 miles old.