[scicala]

"If you truly are experiencing vapor lock, you need to add a 1/4" or more thick phenolic spacer between the carb and intake manifold. It will be necessary to get another carb mounting gasket also. That will most likely end your vapor lock problem."

Vapor lock isn't a carburetor issue. Vapor lock is caused by heat in the fuel delivery system to the carburetor (fuel pump/fuel lines). The gas boils and turns to vapor, which the fuel pump can't pump. The fiber spacer under the carb will help prevent the fuel from boiling in the carb after shutting off a hot engine, and can improve hot starts.

Sal