who has a Pre 67 A body ?

Excuse my ignorance, but what makes a pre '67 A-body so unique that it needs a special forum? Is this strictly a chassis difference, or does it expand to engine, suspension, interior, etc, etc? Don't get me wrong.... if there is truely a difference that warrants a seperate forum them so be it. I just want to know what topics you all expect will be discussed there. But since I do not own a pre '67 car, I personally would not ever read the posts in that forum. Yet, I would hate to miss something that might apply to my post '67 car.