Originally posted by 6inarow:
I understand the difference in vacuum sources. It just surprises me that there is enough vacuum to operate the advance from one carb. For some reason, the ported vacuum is independent of the number of carbs, huh?
You are actually reading/using manifold vacuum so doesn't matter if one carb or 6 as long as manifold vacuum is high enough to operate the advance can being used. The other thing that caused the mfgs. to go to ported vacuum is the effect of having a lot of advance at idle with A/C and auto trans. To keep from stalling you need a higher idling speed which without a solinoid on the carb leads to dieseling.
