Tires to wide

[forestb]

So I have a set of 275 wide tires in the rear that bairly rub on my 62 stepside with a 5 inch drop. They don’t rub on bumps or on regular turns but they do if I make a right hand turn in or out of driveway. Something about how it leans when one tire is hier than the other. I can’t flair the fender since it has just been painted and the last time I tried to flair the fender one of them buckled. So my question is should I get 255’s or 245’s. The 245’s will give me a little more than .5 inches of clearence on each side of the tire. If I get a set of 255’s it will give me around 1/3 an inch on each side. Or is there something else I can do that will help? I have a front sway bar but not a rear. Will that help?