I don't have a set of mill specs to give you definites, but first... how heavy will your truck be? If you vent the wheels you might be running on flats....
You could also try venting your tyres. I hate the idea, personally, but racers do this. They use a really sharp leather punch to do it, so there are no tear points in the hole. A good place would be an inner sidewall, on a thick patch, like raised lettering.