vacuum advance

The amount of vacuum advance is mechanically established in the module. The spring inside that the vacuum works against has an adjustable preloaded that is accessed through the vacuum nipple. This adjustment allows you to adjust the level of vacuum required to start the advance and the level required for full advance.

As stated previously mechanical plus vacuum will be around 50 degrees. But max vacuum occurs at small throttle openings which typically is also a relatively low rpm where you may not have full vacuum advance.

Mechanical advance is strickly rpm dependant and vacuum advance is load dependant.