I HAVE THIS INTAKE AND A 600CFM EDELBROCK CARB ON IT AND IT SEEMS TO HAVE A VACUUM LEAK AT THE BASE EVERYTHING IS NEW, AM I SUPPOSED TO HAVE ONE OF THOSE THIN ADAPTOR PLATES FOR A SPREADBORE-SQUAREBORE INTAKES?
If the carb has equal bores everything should be fine. Get a steel straight edge and make sure the mounting surface of the manifold is flat. Check the carb base plate also. If it is slightly off try using 2 gaskets.