I converted a sweeps dash to SS w/idiots. The SS fuel gauge has a range of motion (E to F) of about 90 deg. My needle moves about 180 deg. Is the fuel gauge sender for an SS different from a Malibu? Not sure if the gauge was working in the sweeps before I made the swap. Thanks.

The fuel sender is the same. (Assuming a 1975) Does the SS fuel gage have a white ceramic block (resistor) screwed on the back?

Sorry, forgot to mention it is a 70. Yes, there is a ceramic insulator on the back of the gauge.

Just thought up a theory: The gauge is supposed to read empty at zero ohms and full at 90 ohms. So, if I am reading over full then I have more resistance in the loop then I should have. I'm thinking a weak ground connection at the sender?

Here is a good article on troubleshooting fuel gauge problems.
http://www.chevelles.com/techref/ftecref18.html