just put a cap on it unless you need it for an air pump ( assume not w/ all the good modifications you have made).
That being said, some situations/distributors respond better to the FULL vacuum there as opposed to the TIMED vacuum port. MOST use the timed port. (That subject has been discussed to death. Look in the "Search" for details if so inclined).
Use one, cap the other. Should be a black rubber plug in the small parts bag.
Good choice of carb,BTW.
If it's good TO you, it's gotta be good FOR you....