Many thanks to all of you who took the time to respond to my plea for help. To recap, while I'm finishing my 67 GT 500 I bought a 71 Torino GT convertible. It would pop back both hot and cold and stall the engine. To make a long one short, your suggestions led me to vacuum. Turned out the vacuum advance diaphram had a small leak!! Runs great now! I am finishing the interior on the GT 500 this week and will start on the brakes next week. #2914 should be on the road by April 08. Happy motoring to all!!!