Initially, the fuel quantity indicators read extremely low. I tried various approaches, but the only thing I coiuld conclude was that the wrong indicators were installed. I tagged the leads, and removed the indicators.
An examination confired my fears. I bougtht two new indicators of the correct type, and installed them. Readings were now believable.
I filled one fuel tank completely, and verified the meter read "full." I emptied the other tank, and verified the meter read "empty."