Classic/Antique Car Repair: 68 Impala Fuel Sending Unit, fuel gauge, fuel sending unit

Question
The fuel gauge is either about 1/4 inch or way over about an inch over full... so from what I have read on here from people with the similar problem is that the fuel level float isn't stuck nor the gauge is broken?? leaving the sending unit as the problem??

Answer
Probably it is the sender, but before you go to all the trouble of changing it, get the new one and hook it up to the wire that goes to the  old sender, and ground the new unit to the bumper with a second wire, and have someone watch the gauge with the key on while you move the float arm around from empty to full. If the gauge responds correctly, you know your problem is the sender - drain the tank and replace it. If the gauge does the same thing it does now, your old sender is fine, you have a problem with the dash unit.

Dick