73 Dart Sport and 4 door 73 Swinger parts interchangeable

The entire front clip is the same- fenders, hood, grille, bumper and brackets etc.

The dash is also a direct swap, as is everything else (heater and AC equipment) as long as your car is an AC car.

Pretty much everything mechanical on the Dart (which is not a Swinger if it’s a 4 door) will swap over. Glass, doors, any bodywork behind the firewall is obviously different. The interior parts other than the dash (seats, interior panels etc) are also obviously different.