I am rebuilding the 2 BBl Carburetor on my 68 bird and the kit has a gasket that goes between the throttle body and the intake manifold that is similar to the one that is on the car but not identical. The edge of the gasket is the same but instead of having two distinct holes for each barrel in the center of the gasket, it is completely open. There appears to be no way that external air can get into the manifold using this gasket, but will it affect the internal mixture? Other kits I have used for other carburetors have not included this gasket; you had to buy it separately. Should I use this gasket, use the old one (would rather not), or order the identical one?