Quad carb setup information help

I received my pin set, drill set and a couple of pin vises today. Also got my Edelbrock unit sync as well. So I've got to fit the gage to either the plastic carb caps or the KRC metal cap. Was wondering what size hole you cut to fit the gage to a cap and how did you fasten it down? Also when you are using it once its mounted on a cap do you put a gasket between the cap and carb? I realize that I need to take care of the timing before I start with the uni-sync.
Rod