There are two large ports and one small port for intake vacuum. In addition to the "higher" one for the ported vacuum advance for the distributor.
One of the "large" ports is to be used for power brake vacuum hose (I would assume the rear since is is closest, then the other for pvc (the front).
The other small one in front next to the large one can be used for intake manifold vacuum for like vacuum operated HEVAC mode doors etc. If you don't need it, plug it with a vacuum cap.
I also see that it is a manual choke carburetor. I like the electric chokes myself. You may want to consider using an electric choke, they are easier to drive with - you don't have to keep adjusting it as it warms up....
