NO! never use RTV on carburetor gaskets.

Try again, make sure the manifold mating surface and the carburetor mating surface are free of any previous gasket residue. Sometimes a scraper or even fine sandpaper are necessary. If the surfaces are clean, and all items are correct (manifold, gaskets, carburetor); everything will seal. If this is a 1967, both the carburetor and manifold must be 1967 (or the factory service 1967) to seal with the original gaskets.

Jon.