I went the 19.5 route on my 3800 and the only thing I don't like is the ride. The tires I have are 14 ply and the least I have seen is 12 ply. I don't haul that much and seldom pull a trailer with the truck so 14 ply tires are overkill but 8 or 10 plys don't exist, or at least I haven't found any.
