I have a 1951 Chevy Pick Up with a 235 that is hard to start when it is hot. It starts great when it is cold and if it is restarted shortly after turning it off (such as when I go to get gas). But if it sets for more than about 10 minutes, it will not start easily. The engine does not seem to turn over as fast when it is hot. I can usually push start it and get it going. After it cools down it will start fine again. It still has manual choke and throtle and foot starter. Any ideas would be appreciated.