school me on differences between Dart, GT, and GTS?

If I'm reading that 69 Dealer Data book correctly, did the "Road-Runner" style hood only come standard only on the GTS and the Swinger 340?

Could you get the 340 in a GT? Or if you ordered the 340 did it bump the trim level up to the GTS simply because you ordered the 340?

and what about the 'vert? Was that only available in the GT and the GTS trim levels?