I have always use permatex on N/A systems.
Its only for the 2 gaskets between the manifold, bakealite spacer and the carbie.
Silicon/silastic etc will eventually dissolve from the fuel.
The rest of your carbie shouldnt need any sealant if all surfaces are flat. If they arent flat - you should make them flat.
Hylomar doesnt stick to aluminium so its not suitable.

Tell your mechanic that if he is a mechanic, he should know the purpose of the bakelite spacer is purely to prevent manifold heat passing to the carbie.