Your Dart and Duster have braces at the bottom of the front fender dogleg. Without them the dogleg would flap around down the front.
Barracuda and 70-72 Dart have lower front valences that the front fender dog leg bolts to. 2 bolts on a 67-69 Barracuda. That keeps the front fender lip from being pushed out easily.
I don’t know if it would help this situation but a person could put a washer between the valence and lower fender dog leg and that would push the lower front fender lip out. The washer would cause the seam to open slightly.
