Intake Manifold Question

I blocked off the heat cross over in my Chrysler with an ld4b intake and 1405 eddy carb. Works great and less heat issues in summer. My Dart has an rpm air gap and 1406, works perfect without the heat cross over. I have cut a small piece of steel to shape and hi temp siliconed it in the hole of the intake gasket to block off the heat crossover with success as well.