Eric,
I know this is an old thread, so I hope you already got the info you were looking for through accomplishment, but I finally finished my mini tub a few weeks ago. With 10" wide wheels with 6.5" back spacing and 28 X 10.5 X 15 slicks, I have 1.5 inches between the slicks and the frame rails and between slicks and fender lips. I can't remember the width of my Dana and I'm not home to measure it; sorry. Sorry it took me so long to follow up.
Brad