Hi, I recently ordered a new bath and it come pri-drilled with the waste/overflow. The problem i'm having is, the pri-drilled hole for the over flow is 2", where my overflow connector is 1.5". This means when i tighten it all up, the washer slips and doesn't create a water tight seal. I've looked around to maybe source a 2" overflow but they are hard to come-by. I was hoping somebody more knowledgeable could suggest the best course of action. Thanks a lot.