Also remember the vacum advance is mostly for part throttle driving when intake vacum is still high. It like ported vacum will drop to about 0 at wide open throttle as the only vacum that wont is venturi vacum which is not a real strong signal but strong enough to work vacum secondary carb diaprhams. Your total mechanical at 36 is not a bad starting point and may be fine for your combo depending at what rpm its all in. My self my dist does not even have a vacum advance as its basically a race dist thats all mechanical advance and I have full mechanical avdance by about 1800 rpm. But the vacum advance is good for a street car as it helps gas milage and helps part throttle power and most cars have 50 to 55 total with all mechanical and vacum advance in. But when you floor it you will only have the mechanical advance because as we said at full throttle you wont have any vacum to work the vacum advance since the throttle plates are wide open there will be no vacum in the intake. It may help you if you know that what they call ported vacum that alot of vacum advances are hooked to are actually intake vacum but the port they hook to is above the throttle plate so it will have no vacum at idle with the throttle plates closed because the port is above the throttle plate. As soon as you step on the gas a bit it uncovers the port and the vacum advance starts working. But it is intake vacum that will drop to 0 when floored. Intake vacum ports are usually refered to that when the vacum port is below the throttle plate or anywhere on the intake as that will be full intake vacum at idle with the throttle plates closed becuase the intake vacum ports are below the throttle plates. Ron