Bob,
Here's another thing to consider: whether or not you want to block off the heat riser port going across the center of the intake manifold. If your carburetor uses an electric or manual choke and you don't live in a cold climate, you might not need that heat going to the intake manifold. There are thicker, composite and metal intake manifold gaskets that do not have openings for that heat riser port. If you used that thicker gasket, you would probably need to use the cork end rail gaskets to make the manifold fit right. Also, you might want to take off that bottom pan so that it would not insulate the intake manifold from the crankcase heat. Just something to consider.