U Joint conversions sometimes does the same....larger wheels up front to use larger rotors, but stays with the factory 16 inch wheels on the dually rear. Overall OD is the same, and only really need to carry a front spare...can limp along if a dually tire blows out. Not ideal, but doable.Zip, thanks for the reply. It looks like a nice coach, but I’m not comfortable with having 2 different rim sizes. If the bolt patterns are the same, why is it different than stock? Ideally it would have a SRW setup (if possible), same rims/ tires all around. I’d also like to know who did the conversion for future support.