First of all, I am not a painter. That said, I did my research and came to the conclusion that SPI semi gloss black epoxy is what I wanted for my 52 Ford frame. I followed the directions, and using an HF purple gun with regulator, commenced to painting the freshly blasted frame. I actually let mixed primer induce overnight for second coat. Apparently, the longer the inducing time, the better the UV resistance is. I could not be happier. Was easy to deal with, and came out quite well. Going to hit it later with a couple more coats once I rivet on some brackets and crossmembers I had removed. Also need to smooth some minor pits. Just wanted to share my experience.
I have used SPI black epoxy primer on the las two cars. It is really great stuff and last I checked it was a lot cheaper than the big name competitors. The thing I really like about it is that it dries with a slight sheen. It works just like a guide coat for long board sanding.