Any variation or inconsistencies ocurring in the point gap will be detrimental to overall performance.  Poor idling characteristics usually come to the top of the list.

On a typical dual point setup, the breaker points are staggered which results in only one set of points actually controlling the timing of the spark to the plugs.  The remaining set of points simply allows the dwell time to be longer so that a better spark at higher rpms can be generated.  An old practice when dual point ignitions were the rage was to simply swap the points to be able to use the set that hadn’t been arcing to save a couple of bucks.  For myself and because the points were staggered, I would wire both sets so I could turn one set off upon going into 3^rd gear (427 Fairlane) and allow the ignition timing to retard about 4°.  This allowed me to run an additional 4° advance in the lower gears.  That’s just food for thought for those of you that are looking for that additional edge at the dragstrip and are actually running a dual point distributor.

The Mallory Rev-Pol or Double-Life distributors and Grant Flamethrowers are dual point but are not of the staggered design.  On these, the breaker points are phased 180° apart and each do equal work.

Converting the distributor to electronic ignition would reduce some of the pain of what you’re going through as the air gap would not be as critical in regards to a bit of variation taking place.  An even better solution although more expensive would be to just purchase one of the new aftermarket electronic distributors for the Y.