Arlie,
In my opinion the single change of replacing a stock 4V intake with a modern aluminum one will do nearly nothing performance wise that you can feel. The reduction in weight is about the only difference. Now couple the change with a bigger cam and headers and you will see its true value in seat of the pants performance.
One thing that I recommend is blocking the exhaust transfer port on the heads with a performance gasket. this helps keep the carb from super heating on hot days. The reason for the exhaust transfer port was to heat up the manifold to prevent "icing" of the carb throats during warm up on cold mornings. Our cars seldom see these conditions and live in nice heated or semi-heated garages.
Rob