33s with the 1.5" Ball Joint Spacer... YES YOU CAN.

I was running 33x12.50 on 15x10 MT with 3-5/8" back spacing, they rubbed a little on the fender. (On E-Bay now)
I am running 33x10.50 on a Stock 15x7 Yota wheels, no rubbing. I think I go full flex now with NO rubbing, or minimal rubbing.