I have a 2008 supercrew 4WD 18" X 7.5” wheels with a 2" leveling kit. I am looking for what the maximum tire size I can put on them with out rubbing I have seen a lot of forums that say 33 but it doesn’t tell the width that they are using?

 

You can squeeze on some 35x12.5 tires with some minor rubbing. To be safe I would go with a 305x65x18 which is close to 34 inches tall. These look great on a leveled 4x4. Just my 2 cent's.

 

I agree. A 35x12.50 will fit but they will rub the control arms slightly at full steering lock.