Zero offset on 14 x 7" rim wheels for P245 60 R14 on stock 1969 Dart, anyone could tell???

Getting a 245 tire on the back of a stock '67-'69 Dart is difficult. 7" wheels with about 4.50" backspacing is where I'd start. You may get lucky and that backspace wheel with the 245 tire will fit without modifying anything. However, the way your car sits (so low) is making the clearance problem even worse. Stock height or even better about 1" higher will help with outer fender clearance.