Reply to "HELP! Autometer Fuel Gauge reading backwards with stock sender"

First, the stock Veglia-Borlotti fuel gauge & zender is the only dependable gauge in the car and I'd think a long time before changing a working gauge. The stock sender reads 0.0 ohms when full and about 200 ohms when empty. Your autometer is undoubtably reversed and no amount of resistors will fix it.
Second, to remove the stock sender, simply use a large, taped-up flat-blade screwdriver between the chrome rear quarter window frame & body, and carefully pry the whole window assembly out of the car. There are no screws; its held in only by gasket friction. Remove the sheet-metal gas tank cover and the sender can then be unscrewed & pulled out thru the window opening without disturbing the powertrain at all. Good luck modifying an Autometer sending unit to read anything like accurately in the tall, peculiarly-shaped Pantera gas tank. Many of us remove the glass from the frame, then put back ONLY the chrome frame, gaining easy access to the big rear window for cleaning.