[DON BEVERS]

Winter time fuel in our area contains "up to" 10% ethanol. This considerably lowers the boiling point of the fuel. The fuel is most prone to boil in the emulsion well of a carburator rather than the bowl as that is where it is thinned out and the air is added. Hot fuel due to heat sink combined with hot air under the hood, (the scoop doesn't begin to cool the air until you are well under way) can be a real problem with a carburated engine. Dead-head type fuel pressure regulators do not allow the fuel to circulate as a fuel injection system does. There are by-pass type regulators available for carb systems and they do help. A heat shield under the carb and insulated fuel lines can also help. Mandated ethanol use is tough on carb systems and it will only get worse as ethanol use grows, new laws are on the way.
On the electrical side, if you are using the black 2-wire plug that comes with all MSD kits, to possibly hook-up your distributor, they are notorious for going intermittant. On the race car, we always replace that with a 2-wire GM weather-pack unit. Completely reliable and easy to get apart for maintance.