67-69 Dodge Dart, which is what?

I always think that like Barracuda 2nd Gen with Barracuda and Barracuda Formula S, Dodge produce Dart and Dart GTS. But I have seen whole a lot different model for 67-69 Dart, ex: (67-69)Dart Post, Dart GT, Dart GTS, Dart 270....

What is the different between GT and GTS? What is Dart Post, Dart 270?

Are these model same basic sheet metal? How could you identify which is GTS? Like 67-69 Barracuda Formula S should have 150 odometer, deluxe interior, heavy duty suspension, emblem call out... what you should look for the GTS?

Those Dodge Dart confusing me!!!!!:confused: