When I had a holley, my car boiled fuel all the time. You could even hear it. I had the carb mounted right on the intake. I first tried a multiple plate/gasket thing that worked so-so. Best is to use a plastic or phoenelic insulator. One with 4 holes works best and if only 1/2 inch thick, it still let the carb stay under the screen. Best solution is to switch to EFI.