Adjusting pump shot

OK to make sure I understand, I will set the timing (initial) at idle with the vaccume advance disconnected from the Carb and the port blocked.

I then adjust the distributer until I get the highest vaccume reading without detonation.

What port on the carb should I be taking the reading from for the Vac Gauge?

once initial Timing is set, if I still have a problem then what?