[Old Henry]

The most typical problem with vapor lock is vaporization of the fuel in the fuel pump, not total boiling out of the fuel in the carburetor bowl. Anyone that's ever had vapor lock knows that if you wait long enough the fuel pump will cool down enough to condense the fuel back into liquid so that the pump will pump. (That can even be rushed by pouring water on the pump, pushing a half grapefruit onto the top of the pump, etc). So, overheating the engine then leaving it all night is, of course, going to allow the pump to cool and condense the fuel and have no problems starting in the morning. The true test would be taking a 30 mile drive in 90+ temperatures, stopping and parking in the sun without opening the hood for 20 minutes, then starting up and seeing what happens. I look forward to the results of that test. Let us know how it goes.