yet another fuel gauge thread - reads full all the time
How many gallons are in the tank.
You might need to remove 5 plus gallon s for the tank to read anything g other than full.
Aftermarket senders are far off.
Look at the chart
Product Review: A100 Fuel Sender For 67 Dart
Also your bending of the arm might have moved the sender into a place where it reads full for an extended time.
Btw
You can not bend the sender arm to make the sender more accurate
The after market senders are too liner for the shape of our tanks and the curve the gauge is expecting