Back before I had kids, I used to daily drive a 68 Mustang in the summer heat in Texas. It was bad enough that the car didn’t have AC, but the real insult is that when I would stop for gas I knew it was going to take me a while to get the car to start back up. I chalked that up to a quirk of a car from the 60′s. The thought that the issue with starting might be related to heat soak never entered my mind. I always associate heat soak with forced induction applications, not NA cars.
Edelbrock has posted up a very interesting tech tip that helps drivers of carbureted vehicles figure out what is causing an issue where the car might not start back up easily. If after driving the car for a while and then shutting the car off and then within the same hour you parked the car, it is hard to fire back up. heat soak could be the issue. The heat from the hot engine block and exhaust can soak into the carburetor and fuel lines making it hard to fire the car up. Thankfully, Edelbrock has some tips to fix this problem if you have it.
Edelbrock says that the first thing you need to do is be sure your fuel line is routed away from the hot exhaust and engine block. Once you ensure that the fuel line routing isn’t causing your heat soak issues you can turn to a spacer between the carburetor and the intake manifold. You don’t want just any spacer though; you want to get one that is made from wood fiber laminate or black phenolic plastic. Aluminum spacers offer little help according to Edelbrock. You will also want to be sure that you have the hood clearance for a spacer as well. Naturally, Edelbrock offers a full line of spacers so check out their wares and see if they might fix your hard start issues.