What carb do I have?

I bought a Holley 650 a couple of years ago and never took it out of the box. I asked for a Holley 650 double pumper but before it arrived I sold the vehicle it was going on. The part number on the box is 0-80783S, and description of mechanical secondaries and manual choke. My problem is I am going to sell it for a 750 but I noticed this carb has vacuum secondaries and an electric choke. How can I tell what carb this really is. It definitely is not the part number on the box.(got to love Schucks)