Your camber posted is within stock specifications. It's simple really. The tires only rub on massive bumps. During normal driving no interference. If it bothers you, one logical choice, narrower tires. The geometry of the suspension has the top of the rear tires moving inwards under compression. Since the camber is within factory specifications don't bother with the adjustable camber arms unless you want to keep the wider tires and adjust the camber so the tires fit without rubbing. I'm lowered as far as possible and rub in the same place with a 275 tire. Heck, I'm lowered to the point that I rub the stock rubber and tires on huge dips. But I'm also aligned with a bunch or rear camber. What do you want and what's important to you?

Les