64 Dart cluster connector
On my testing chart...
Starting at 18 gal on the right
The gauge will show about 1/2 tank when only 6 gallons have been used. 9 gallons used would be 1/2 tank.
The next 4 gallons will bring the gauge to 1/4
That's about 10 gallons used. The gauge should show about 1/2.
Keep in mind my gauge ( not the sender) and your gauge will not be completely the same. (Age, abuse, environment)
BUT they should be close.