*Vacuum around 15", 15" is too low for a engine, it should read a fairly steady 19" and when you step on it, it will drop to around 3-5" (not 0"). Adjust the idle and air screws on the carb to get it to around 19". That will help first off. (It bounces a little but that should improve as it runs more (valves maybe a little sticky).
If I adjust air/fuel screws out further it starts back firing thru muffler every so often, really want to think not getting enough voltage 
Checking ignition switch next! Condenser is Echlin FA54. Already did compression test and all cylinders had better than 80 lbs AND I also poured marvel mystery oil down each cylinder too plus added some to the fuel tank.
Starting point is 1 and a 1/4 turns out on air/fuel mixer screws.You might need to adjust the idle screw also
. Set the carb air/fuel screws to 1 and 1/4 turns, then adjust the idle screw to keep it running at a decent rpm.... Then fine tune the air/fuel screws to a vacuum gauge to 18-20". I'm not saying this will help the intermittent running, almost certain it won't, but should help fuel delivery, etc.