Couple things you might want to do before you open the tank:
1: Lay hands on a new fuel tank sender rubber gasket
2: Prepare a wire about 14" long (better measure to make sure) to go from
a fuel tank sender body mounting screws to a fuel tank mounting screw to assure
a good sender ground. This can be a problem area with gas gauge senders and
an ounce of prevention is worth a pound of cure. Crimp ring lugs on each end
of the wire. Bare wire would work but use insulated because of galvanic
reaction between the wire and the gas tank exterior in what is often a moist
environment. You don't need to rust that baby through from the outside top!
btw I rusted my 164's tank through from the outside with trapped water under
the trunk floor. Fortunately I had a tank out of a 142 that fit.
--
George Downs, Bartlesville, Oklahoma, Central US