[My427stang]

I dont think most of the nation can understand the heat off of the pavement, especially from the desert.

Mine ran great everywhere, until I got stationed at Nellis AFB. I then fought percolation like you, pavement temps of 150+ are something east coasters (like I was) never even considered.

High fuel pressure from pump to as close to the carb helps vapor lock, but you have to keep heat away from the carb because it operates at zero pressure. Ultimately, even a carb heat shield will allow the heat to saturate if you dont have airflow to take the heat away.

Look to have a return line to keep fuel as cool as it can be, at the starting point, insulate lines from ground heat where you can as well, and make sure the carb isnt buried in goodies preventing airflow around the body of the carb. Anything you can do to get airflow AROUND the carb, not just INTO it will help dramatically

In addition, drop base air cleaners act as heat umbrellas, so any way you can run a flat base will help as well to let heat evacuate

Finally, west coast fuel, and 50 state winter fuel will flash off much easier at low PSI and zero psi internal to the fuel bowls, I wouldnt expect AVGAS to have that issue though, so you could always increase your percentage

Ultimately, the real "perfect fix" is EFI, but I bet you can get a lot closer with some heat management