I guess the real answer to the question is that all 1974 360 Dart Sports had the higher horsepower 360 and an "L" code for the engine in the VIN. 3,314 of them were made...
Correct, Dart Sport never had a 2 barrel option. 2 barrel was available on some of the bigger cars and some of the F/M/J bodies. Not sure about the cam sizes in '75-'76 Dart sport 360-4.