I am currently in Naples, FL - very warm. When I drive my 66 in warm weather, it runs fine for about the first 45 minutes. After that the engine stalls if I’m in neutral at a stop light, for example. Doesn’t run smoothly at all and always seems like it’s going to stall out. I run a mixture of Exxon high test and 110 octane racing fuel.
Any thoughts
Thanks

 

First thing that comes to mind is coil, you may notice the time starting to shorten up before issues begin.
The other thing to look at will be fuel pressure, possibly one of the check valves in the pump gets sticky when hot.

 

Welcome to the forum. How easily does it restart after the stall? If you have to pump it a lot to get it to restart then I would suspect a fuel issue. If not then I would suspect, like 74Harley said, that you would need to look at the ignition system.