[rotorwrench]

Is this an original King Seeley type sending unit or is this one of the late aftermarket type senders? It's common to have problems with accuracy on the late replacement senders due to them not having the same type of electrical function as the OEM KS units. Late repros are rheostat types with specific Ohms reading from empty to full and the OEM units are a variable current draw by heating coil type mechanism. The quantity indicator units don't have provisions for adjustments.

Its kind of a hit or miss indication with the late type senders installed. They generally can be adjusted with the float mechanism for full to empty but that's about it.