I have an old plastic Harwood cell in my car, 12ga. just under 10" tall. I plan to start driving it, so I would like a fuel gauge in it. I know zilch about electricity, so could someone suggest a sending unit and gauge I could use. Jeg's didnt have much selection, and it seemes the gauge and unit have to be compatable with each other?? I would like to use an Autometer gauge if possible so it matches, but not imperitive. Thanks in advance.