Originally Posted by CHEVILLAC
Ok, I know ported vacuum for the vacuum advance is hooked to the carb so I'm guessing it is operated in a similar way as the vacuum secondaries, otherwise a motor that has very little manifold vacuum wouldn't be able to operate the advance. If the motor runs well as it is, what would be the advantage of adding the vacuum advance back into the equation? Will it be better for for driving conditions between idle and WOT?
Ported vacuum (passenger side
vacuum port on the Edelbrock carb) is only there when the throttle blades are opened. When closed, no vacuum. What that means when applied to a vacuum advance is there will be no added advance at idle. You already have a high enough amount of initial advance (or you should
have, like 20 degrees-plus) for the engine to idle well w/that cam, so no additional advance is needed, or wanted.
The vacuum advance will only add advance to your engine at light throttle/light load conditions. This helps the engine to run smoother, maybe a tick cooler, and will use less fuel. There are no downsides to using it- as long as it's done as I've outlined.
Once you get it running, check the initial and total advance to be sure it's what it should be.