Help with my 15x10 ralley wheel idea...

I ran some 15X10 weld wheels 5" BS on my Demon. No tubs but I did move the leaf springs in 3/4 on each side. I think you are about right on the back spacing. It is probably going to depend on the tire size if you have rubbing on leaf springs or fender lips. It will be a tight fit with stock suspension.

Think I was running a 28 X 12.50 MT quick time tire. I would get some fender lip rub on big bumps