Quickfuel Slayer 450 CFM carb gasket

I will be running an Aussiespeed Hurricane long runner intake with a 4 barrel quickfuel Slayer 450 CFM carb. Since I live in a colder climate I will be running a manifold pre heater hooked to my heater hoses. I was told by Quickfuel to not run the heat resistant carburetor gasket for this application. In another forum someone recommended a 1/2 inch thick standard carb gasket for this application. I have searched for one and I am not finding anything thicker than 1/4 inch. So what is the purpose of a thicker gasket, and do I really need one?