1989 ford ranger sending unit help

1989 Ford Ranger 6 cyl Two Wheel Drive Automatic 

I need a new FUEL SENDING UNIT but when I talked to a local auto supplier they asked if the sending unit was on the passenger or driver side. Is there anyway I can tell which sending unit I need to purchase without dropping the fuel tank?

Apparently, the sending unit for the “drivers side” is twice the price of the passenger side but when I searched EBAY to purchase a sending unit it never indicated whether it was for the drivers or passenger ¬†side.