I have a couple of old Holley carbs and I can't identify one of them. The first I figured out based on the code (D8PE), that being a generic 1978 carb.

The other one is a mystery. It was on my 68 302-4V coupe when I bought it but was probably not the original carb. The only identifying mark I could find on the carb is this:

LIST 3220-S
793

Does anyone know how to identify it? Maybe there's another code on it somewhere that I didn't see.