Just installed a universal Automer sender with a after market gauge, both are rated at 240/33 ohms, the problem is the gas tank is full and is reading near 1/4 tank with the sender in the tank . With the sender out of the tank, when the float is moved up "full" it reads empty, when the float is down "empty" it reads full.
Any suggestions? On a 1955 Ford Fairlane Town Sedan.

Claim to fame is the car was used as an extra in the movie Diner with Micky Rourke, Steve Gootenburg, Paul Riser and Kevin Bacon.