[Bruce Edwards]

Ok dumb question time. Why do you think it is the Holley?? If it dies when it gets hot it sounds more like a vapor lock or ignition failure. Are you running an electric on mechanical pump? When the car dies does the tach move when you try to start it? If it is an electric tach it should bounce with every turn of the engine. If the Holley is out of fuel you can kick it a time or two to shoot the last of the fuel out of the pump. The car should start and then die again if the ignition is working. If it is not you should be able to see fuel spray down the carb as you open the throttle but the car will still not start.
Since the you did not say you ever say the temp get in to the red I can not see it being a head gasket type problem.
Can you give us all a bit more to go on??