That's correct, not a converter just a 2 part primer. If the pits are really deep and can't be sandblasted, converter is really the way to go before primer. For the last 10 years or so I've been using Picklex 20.
http://www.picklex20.com/1142290.html
Another benefit of Picklex is when you are going to do partial work and leave bare metal unprotected for an extended period, just spray the bare metal with Picklex, keep it dry, and it will remain that way indefinitely (no rust). I have a mint condition grille in the basement I was saving for chroming. I had it soda blasted about 5 years ago. As soon as I cleaned it up I sprayed it with Picklex 20 and it looks exactly how it did years ago.
Before that I used the red stuff Eastwood sells (years before they bought the rights) and it worked fine, although it's thicker and goes on like paint. The problem with Eastwood is their excessive pricing.