1948 Chevrolet 235 Pick-up, Carter YF Carb. Question: the carburetor schematic shows a gasket that goes on top of the Insulator Plate, between the Carb (throttle body) and the insulator plate. Should there be a 2nd gasket that goes on the bottom of the insulator plate between the insulator plate and the Intake manifold? OR just the insulator plate on the manifold no gasket?