[northcountry67]

It sounds to me more like a spark advance problem. Remove the dizzy cap, disconnect the vacuum line to the dizzy and put suction to it with your mouth. Hold the suction and see if the advance holds or moves. With vacuum, the spark should advance and hold as long as there is vacuum and should return to normal when you release the vacuum. Check your vacuum lines first. If the advance slowly moves with constant vacuum, you have a bad advance.