Try
http://www.superdutydiesel.com/
Also, there's lot of good info over at dieselplace.com
Our gravedigger has a new SD...I'll run it by him and see if it's doable...why isn't it, doable? On the Chevys the rears are the same, I believe, as I see lots of folks around here with duallys simply take off the inner wheels and run the single outer wheels/tires with the offset dually wheel...looks decent, actually?