I have 30x9.50x15s on the rear of my truck. It has 70's era Chevy truck wheels on it, not sure of the dimension, but not big ones. the front has some dinky little 215/70/15s on it, but I will upgrade them to match the rears when money is available. The previous owner had 30x9.50s all the way around and I don't see any evidence of rubbing.
Devin