Engine speeds up when brake is pushed

The valves are hydraulic so I can't adjust. I changed the carb to a edelbrock and never touched the floats, not sure when they should be or how to adjust. Would I hook up the vacume gauge to the large hole at the base carb, and how many lbs of vacume should I have, or am I just trying to get it as high as I can by adjusting the air mixture screws.