1969 Dart tire and wheel sizes

I put together a set of 15x7 rims from Wheel Vintiques (bought from Summit) with 255/60-15 Cooper Cobras on them for my 69 Dart. They are too wide, but some of that is because I went to a 8.75 rear end with Dr. Diff BBP axles. His axle flanges are thicker than stock by about 1/4" or so. Even with the stock axles (I have a set that have been redrilled for BBP) it would still be pretty tight. The spring side isn't so bad but the fender side needs help. I need to go to 245/60-15's or roll the fender lips, or both. YMMV, these cars are all a little different when it comes to this sort of thing.

Oh, and the two sides are not identical. One is closer than the other. Go figure...