I am by no means a distributor expert, however here is what I know from my experience.
There are two different types of distributor advances, ones that use a vacuum all the time, or ones that use the vacuum as the engine revs higher and needs to advance the timing. My HEI distributor advance is connected to my carburetor (Edelbrock 1406). I am probably not completely correct on this.
So, for the experts on here to be able to help you, they're going to need to know what carb, distributor, etc you have. More info = more better answers.
