you can fit 245/75x16 on standard steels with little problem as i have a friend who used to run that size on his commercial, you may have to adjust the steering stops and under articulation it may catch on the rear arch.
I used to run 235/70x16 technic amazons on my V8 and they used to catch under extreme articulation but not much, i now have 265/75x16 fitted but i have lifted by an inch. they dont catch much as the offset of the wheel tends to tuck them into the arches but they do catch badly on the rear of the rear arch..so i cut it off and i have found when the front axle articulates they will touch the spring turrets
heres a pic with 265,s on