Yes, the trans and smog/no smog determines the carb ID code for a '66. If you don't have emissions, you'll be needing a C6ZF-B.
Incidentally, I have a local friend with a concours-restored C6ZF-B with a 5HB date on the tag that he would like to sell. If interested, send me a PM. Think he was looking for around $500 for it.