The back spacing is the key. I have 8" ramcharger wheels and they will NOT fit with 275/60 or 255/70 15's. It's the "bulge" a couple inches up on the "inside" of the outer whee well. If the BS was 4.5 or 5 it would be fine. At least on a Coronet. I don't know if the Plymouth has the same "bulge".
