Mine are stock steels, with the center piece that uses the three screws from the back, and I like them cause I can paint em black if I want or leave em bare. but I HAVE taken it off road with eth stock rims and 235's and so far as long as I don't bottom out in mud I'm ok, all I have to do is keep traction on at least two tires either in front, back or on either side, or if worse comes to worse I overcome the open diffs with the brake, but so far the 29's have done me no wrong.
I can go as big as 30's without rubbing at all, so next time I need tires it depends on which is cheaper, 29's or30's