Well I’m not gonna take credit for the wording of this definition but; “A gasket is a mechanical seal that fills the space between two objects, generally to prevent leakage between the two objects while under compression or vacuum. It is usually desirable that the gasket be made from a material that is to some degree compressible such that it tightly fills the space it is designed for, including any slight irregularities.”

Now then, I will lay claim to making the same statement as above many times in my own words when the subject came up. I have always approached two machined cast iron surfaces seperated with a chunk of hard plastic (Bakelite) as a situation that needed “gasketing.”
There is absolutely no way that insulator is going to conform to the machined suface to form a perfect seal and since a vacuum tight system is the objective here I have always used gaskets with the insulator, top and bottom. Some are going to say that we can live with a slight vacuum leak between the insulator and the Manifold and/or Throttle body but I ask, why should we have to live with ANY vacuum leaks at all!
I’ve Never had a problem with installing a carb this way and don’t see why there would ever be a problem with it.
Also keeping a path to a vacuum port in the base of a carburetor open in any situation is only common sense if one fully understands the system.
Denny Graham
Sandwich, IL

Denny G
Sandwich, IL