[68 P.O.S.]

Originally Posted by truckster

As for the vacuum advance - ported vacuum (Edelbrock calls it "timed vacuum") was an early component of emissions control. The purpose behind it was to retard the spark at idle so the fuel/air mixture would be burning as it exited the exhaust ports. That was intended to increase exhaust temperature to burn off more hydrocarbons, but all it really accomplishes is burning excess fuel. Do yourself a favor and block off the ported vacuum and connect your vacuum advance to manifold vacuum. You'll get quicker response and better fuel economy.

This^^^ I couldn't agree more