Its what you call the style over here man short and wide! i think it looks sweet! i love that low profile swamper look.33's are going to look awefully small (w/3" level)...not to mention very low profile..
but you can run 37x12's on the factory rim without rubbing with a 2" leveling kit....well i got some bad news, i dont think you will be able to clear the 33 iroks with the 3" spacer, i just got my iroks mounted on my 20x12s and they rub bad with the 2" spacer. so you maybe able to clear them with a 4.5" lift
the 33s on 20x12s wont clean with a 2" levelin kit. the truck wont even make a turn4.5 inches seems overkill for 33s but i guess thats the west coast style?