Start by getting a shroud, I am willing to bet that with just the proper shroud your issues will be over. Put a vacuum gauge to manifold vacuum and adjust your idle speed screws on the carburetor to the highest vacuum you see and then give the screws another 1/4 turn rich, make sure you have no vacuum leaks. I have seen cars running hot at idle because they were too lean on the idle circuit. You are having heat soak issues, make sure that you have a thick gasket under the carb like what was used with the stock thermoquads on the 340 engines, that will help mitigate some of the carb heat soak, you could also put some insulation on the fuel filter and fuel lines going to the carb.