Need to know by tomorrow! Is this the right float?

Heck I have had customers bring there carb's in and lay them on the counter when I worked as a counterman at NAPA. I would bring the carb with me and a good counterman would pull a regular screwdriver out and open it to make sure it's the correct float... If it is a bad float you can test it your self, but I would think it's out of adjustment and sticking/rubbing the sides or the needle (shut off seat) check if the float and needle assembly is free moving and is opening and closing.
They will have 2 rebuild kits, a complete rebuild and a gasket and seat kit.

Hope this helps. It is tomorrow already