I dont think the diameter is going to be an issue. You may get a few responses, and I'll give ou one, but I have found that the rear ends arent always centered under the car. I your going to stuff everything you can, take LOTS of measurements. I am running 15 x 7 cop car rallies on my 71 dart. They have 4.25" of BS and fit perfect on the drivers side with about 9/16" of clearance on both sides of the tire (245/60-15). The passenger side, however, rubs the fender lip. I'm going to have to roll it to fit the tire on that side. If I were you, I would jack the car up and take off a wheel. Measure from the face of the drum to the inner fender with a plumb bob or whatever you have that will work. Also measure to the leaf spring to figure our backpacing. I would guess that if you want to run 8's you need to be spot on. I hope someone else will chime in because I've never worked on those specific models- just mine. Check out the wheels and tires section and you will learn a lot in just a few minutes. Hope this helps.
Mike
