I'm sure, that "piece of metal" as u call it is your spacer for your carb, and the other is the gasket. Both need to stay on. When u look down the carb, u should see the same size holes all the way down from the carb, if the spacer is too much smaller, I think u can find another one the will have the same size as the carb. But basicly u can't do anything onless u buy a 4bbl carb and a new intake manifold. The 2bbl is why u don't have much power. The spacer, I'm sure, if u look close enough, u will see some vaccuum lines going to it, prob one from the valve cover, and others for, lets say, power brakes, tranny, whatever.
U can buy a new bigger 2bbl from holley, w/o changinf your intake manifold. Holley makes a nice 500cfm 2bbl, thats another way of getting more power.
By the way, are u still running smog equipment?
