I found a photo on the web, with a dual quad intake manifold using carburetor spacers. I guess these would help with keeping the carburetors from the problem of heat saturation from the engine. Actually, I keep this photo in my computers photo album, because I really like the way the accelerator linkage is designed.
^^^^^^Center squirters with jet plates on a Y-block manifold. 1/2” aluminum adapters small base to large base. I’m thinking it might have cold condensation drops on the outside in a mile or two...^^^^^^
Those Thermo-Quads really worked well once they made it into the hands of someone who knew how to prep them for street use....
I spoke with an Edelbrock tech. rep at a Good Guys show several years ago about the same issued on my 34. Said implicitly it's the reformulated fuel causing rapid evaporation. Same problem on my AV8 using Holley 94's. Electric fuel pump to prime the carbs works well.
My ex wife's 57 Ford 312 was so bad about boiling fuel with an Edelbrock carb that on a really hot Florida summer day you had to avoid drive through eatery lines because it would start to idle rough. as soon as you pulled out and got some air flow it would straighten out. I made a spacer out of marine plywood and it cured most of the evaporation issues and cured the idle issues when I went to Taco Bell. I finally just bought a new 600 Holley and never looked back. Have you tried installing a fan in the engine compartment to help cool the compartment. I had to do that on my motor home to get rid of some of the heat in the summer time when I was pulling my race car trailer. You couldn't touch parts of the engine cover when it was really hot out.
I have a 1300 cfm pusher fan in front of the stock fan that comes on when temp goes over 195 deg but is off when engine stops.
Basically there is no sufficient difference between the two just that they all evaporate at different rates based on temp ect
The Jalopy Journal
