1968 Dart GTS 340

1968FormulaS340 said
If a person is advertising a car as a Formula S, GTS or whatever, this implies added value. You are paying a premium for a performance model.

It is reasonable to ask for and expect some kind of documentation that will show you are getting what you are paying for.

Quite right.

And to answer someone else's question, the "M" engine designation meant "special order V8", which usually means a 440 in an A body. For a 69 1/2 B body (which was never referred to as a 69 1/2 by the factory) meant a 440+6.