My tach and gas gauge quit working

Hello, the fuel gauge receives information from a sending unit at the fuel pump. Did you swap the sending unit over to the new pump? If not, the pump may have come with a new one already. Ensure all wiring is installed properly. The tach does not relate to this, so it's hard to say why that is not working. It's possible that you have an instrument cluster issue too, but doubtful. Before all, however, please be sure to check for any blown fuses!