Need 15" BFG size options for Dads 67 cuda

I'm running a 205/60-15 on a 7" wide 4¼" offset on my 73 Dart. No problems under any circumstances.

Check camber on the wheel that's wearing strangely. A-body Mopars have a tendency to drag the inside front wheel when turning sharp and going quickly. This can cause the wear pattern you describe. Besides the speed of the turn, body roll is one of the culprits. Body roll can be minimized wit the help of an anti-roll bar.