Dat same ole subject wheels and tires

With a 6" wheel 215/65-15 is about the right diameter and width for the front.

Opinions will vary greatly.

On the rear of my '69 Dart (same body as yours) I had troble with 235/60 tires rubbing both inner and outer fenders with S/S springs, 7" wheels, and 4.25 backspacing. Some people have run 235, up to 255, tires on the rear of these Darts with "no modifications" but I'd like to know how.