I have never drilled a nuvo38. But I have drilled several dozen tanks from 10's all the way up to my 120. My first suggestion is to find out if the tank can even be drilled. I would contact the manufacture of the tank to see if the glass is tempered or not. If it is tempered, then that is the end of the story for drilling. You would need a HOB overflow. If it is not tempered, then you can drill it. I would suggest watching a few videos on it or find someone local to you who can do it. Not sure who would be available local to you, I am between London and Windsor.