I had a 318 with headers, cam, similar carb and lived in his same city and had very similar issues. No manner of metering rod, jet, or fuel pump changes ever fixed it either. Efi with high pressure fuel delivery did. I found the Edelbrock carbs to quite temperature sensitive and tracked everything with a wbo2 and ir thermometer. I'm not recommending doc go to efi, I'm fact I recommend against it (and said as much), but no matter what I did I could never get rid of the heat related issues with that damn Edelbrock carb. My buddy who's into e bodies always ran holley and never had a single issue... So that's where my experience comes from.
Living with a hot rod in the southwest is a completely different animal than in most places. Hard to believe but true.
