The Bel Air looks like it doesn't have the F41 package going by the photos. The one picture that shows the mufflers and one rear wheel should also show part of the rear sway bar. It's not there. They may be misinformed. There's some odd wire routing going on that I wonder about. The ad is a little vague. For a car with such low milage it has been more modified that I would think.
I emailed him some questions and picture requests. We'll see what he says.
The Caprice is something that I wouldn't mind having for more of a driver thing. The air conditioning issue is something that would have to be rectified since it appears to have the factory Comfortron system. It was very troublesome. Replacing it with a factory 4-Season system might be the way to go.