15x10?
I did a mini tub & triangulated 4 link and got 325/50/15's on a 10" Steelie Wheel with 5.5 Backspace. I did Narrow a B Body Rearend 3 3/4" on each side and they sit dead center in the wheel well. This puts right at 12" of rubber on the ground. This is on a 67 Dart GT.
Here is a link that shows the whole process of what it took me to do the Mini Tub, 4 Link etc.
http://www.forabodiesonly.com/mopar/showthread.php?t=101437