How much coolant temperature?
Is the exhaust crossover on the intake open?
Mechanical fuel pump?
The only part I’ve ever seen drop actual carb temp is called “Cool Carb” and it’s two pieces.
I’ve tried every thing you can think of and not one of them ever dropped carb temperature.
To run a return system you need a fuel pressure regulator that has a bypass feature.
Then you have to run a line from that regulator to the tank.
It’s unusual for a Holley to have this issue. Usually it’s when coolant temperatures are above 195 degrees and you have an iron intake manifold with the heat crossover open.