ffbo? would anyone join a for f-bodies only

(re K-cars badged "Dart" in Mexico)
But they're not related in concept

Sure they are! Take a look at the Chrysler 2.2/2.5 and slant-6 engines and you will see a great deal of engineering philosophy and execution in common—no real surprise, because many of the same engineers worked on both engine families. As for the F-body being "related in concept" to the A-body, well, sure, and so is the Chevrolet Nova and the Ford Fairmont: rear-drive sedans, coupes and wagons with wheelbases of around 108 to 112 inches, considered "compact" at the time they were sold, available with inline-6 or V8 engines and 3-speed automatic transmissions, disc brakes up front and drums in the rear, and physically almost indistinguishable from one another if you're more than 2 blocks away and/or don't care.

Yeah, the Aspen was badged as the Dart in Mexico, and the Volaré was badged as the Valiant Volaré. So? That doesn't make the F-body any more related to the A-body than it already isn't.

I have no particular opinion on whether there should be an FFBO site or whatever, but "Oh, hey, F-bodies are related to A-bodies because the F-body replaced the A-body in 1976" is not an especially thoughtful statement.