I can't seem to get my vacuum more than 14 (?) on the gauge. so I decided to test for leaks. I used a vacuum guage to test the vacuum advance by connecting it to the hose from the distributor and "sucking" the vacuum advance. The advance does move but the gauge loses vacuum over 2-3 seconds. Does this mean that the gauge is bad or is this normal. I am assuming that there is no leak in the line but I will check that next if necessary. I have not had the engine running since last fall. This is new rebuild so the engine should be ok. What tests would you do next to make sure vacuum is up to specs?