Quote:

If you are driving on the street and your distributor has a vacuum advance unit on it, use it. Most Mopars ( from the factory ) ran ported vacuum. If you are running stock stuff, run ported vacuum. If you are running a pretty hot cam and have idle issues. switch over to manifold vacuum. The extra advance at idle will help with idle quality. Mileage will be better if you use the vacuum advance, not to mention the motor will run cooler.



People who know nothing about tuning a performance car compensate by putting the vacuum advance on manifold vacuum. It helps hold the idle for those with lack of tuning ability. But at WOT there is no vacuum and you give up a huge amount of Performance! Some people should not be offering up advice period!