Quote:


It was plugged into the front port on the Edelbrock carb.

What are the benefits to the extra vacuum advance at 45-50. Better MPG's or cruising?



That's right idle vacuum was pulling the cruise advance on. but under heavy load and WOT there is little or no vacuum so it falls to your incorrectly set total. thus the hesitation and popping and all round poor WOT performance and yes the vacuum advance is a crude cruising gas mileage enhancer. Under light throttle (low cylinder pressure) the ported vacuum will have vacuum as it is exposed to manifold vacuum and allows more timing then normally unable to help carry the motor a bit this giving a little (and I mean little) more gas mileage.
when under heavier load low vacuum occures and it is taken back out of the equation and your total mechanical is all you have.
I personally think trying to mix vacuum advance (on the right ported vacuum) has no real place on a performance car.