I have a 68 ss with a 355 400 hp 650 hooley double pumper. Twice now I have either just started a short cruise or retuned from one when the car just shut down. once when coming to a stop and the other when I was cruisin around 35 mph. After tring to start the car for about 20 minutes it finally started. I failed to mention on the 35 mph ride it was raining. Could this be a vapor lock and how could I solve this problem.