IIRC, there was only a couple of brands of 255's that will not bulge on the stock 7.5 rim and I think they were the cheap chinese brand crap. I know there's been quite a few that have done it and never had issues, but I won't recommend it.What about a 255/45? That brings you much closer to the correct diameter, only off by 0.8% instead of 2.1% with the 245