help with vacuum advance

A mity-vac can be your friend. Get a mity-vac with vacuum gauge. It can be used to measure engine vacuum, checking the vacuum available at the port used for the vacuum advance. It can also be connected directly to the vacuum advance can and by using the hand pump, and timing light, you can measure and record timing change with vacuum. It is necessary to keep engine rpm steady, and a timing tape. So you will need a tach too. By keeping engine rpm steady, the rpm advance will stay the same. Rpm goes up when advancing timing, so you will to control throttle.