Still a little confusion here, the hole and bolt pattern has to match the sending unit you are going to be using. I would make the pattern to match the sending unit. If you do not currently have the sending unit that might be the place to start. If I was attempting this I would locate a sending unit and then fabricate a pattern to match the sender and transfer that to the fuel tank.As I told you before, I don´t have the original tank and I'm trying restore it. For that reason one of the things I need now is the tank hole dimensions. So, I asked for the sending unit gasket dimensions who are the same than the tank hole