Ignition Problems

The good part is the problem sounds like you can easily reproduce it. Get a can of starter fluid (Walmart, etc) and spray shots down the carburetor throat. If it idles much smoother, your "electrical problem" is actually "not enough fuel at idle", i.e. "lean". If you have a Holley 1920 carburetor, I wouldn't be surprised (please tell us). Spark misfire is most common at WOT and low speed, like when accelerating on a freeway on-ramp.