69 Dart GT Conv. 340-6pak

The width is not as much an issue as the 15". If you go with 15's on the front, and back up with the wheel turned, it will hit the lower corner part of the fender opening. It happened to me, and it pulled the fender out. I had to make adjustable lower fender support rods and adjust them out far enough so the fender would not contact the tire. The factory wheel well is actually tilted in at the bottom lower front wheel opening. 15 X 6" may help a little, but a very narrow tire will be needed also. All these issues are what drove me to lengthen the wheel wells.