Another problem is that vacuum lines are very often not needed, or not needed "any longer" so unless you know all the details it is really tough. Many just get capped off. Of course depending on carb you might have more or less. Might be easier to check of the essential list, of which I will forget some i'm sure:

Line to the master cylinder.
PCV
Choke? depends on the system.
Distributor
transmission?

Ones that often get capped:
Line that goes to original air cleaner, to run the heat riser valve.
Choke