There was a period of time when Holley carbs could fall victim to “zinc pest” if they sat around for a while.
But the carbs on that Hemi are probably aluminum.
5 mins pulling the bowls off would answer the question whether a kit would fix them or not.
They are aluminum and have been gone through and have very very low hours on them-unless they are full of corrosion it would be an extremely easy fix J.Rob