No, do not get the desired total initial timing with vacuum advance by adjusting the advance can. Disconnect the vacuum advance and plug the port on the carburetor.

Now set your initial timing at 16 degrees.

THEN plug the vacuum advance in. It really doesn't matter exactly what the vacuum advance does for full throttle performance, but set it up how FBO advised. If it isn't 30 degrees once the vacuum advance is hooked up (to manifold vacuum) then adjust the vacuum advance can accordingly.

Your timing is probably a few degrees retarded of the recommendation from FBO.

Don't forget that idle speed and the timing will both effect vacuum at idle, and thus will effect how strongly the vacuum advance can be pulled. Make sure that the car is up to running temperature and that the idle speed is set where you want it with the advance hooked up to check your initial timing with the vacuum advance before you fiddle with the adjustment in the vacuum advance can.


EDIT: I may be misunderstanding what you did, but confirm that you set it up the way that I recommended.