Not an a-body, but me and a friend painted the top half of my Aspen a few years ago. We used the SEM Hot Rod Black kit from KMS Tools.
Very low-buck. We did zero bodywork. No primer. We sanded the top half, blew it off, wiped it down and sprayed it. We did the whole job in my buddy's upholstery shop, in one weekend, for about $200, including fast food and cheap beer.
All in all, not bad results. If we'd done more prep it would've turned out better. The change from the pale yellow upper to semi gloss black really transformed the car.