Have you checked to make sure your vacuum advance is working? You can check this by looking at the distributor with the engine running, and reach over and goose the throttle. You should see the whole distributor rotate 10 or 12 degrees. If it doesn't rotate, you may have a blown diaphram in the vacuum advance. This will affect your performance, and will cause a vacuum leak.
I would also check your gauge and make sure it is reading zero when it is not connected. Your altitude will affect the reading. It should have an adjustment to set it to zero.
Good luck!
Kurt
