Help us out a bit more on the project.
What is the purpose of having a fuel level reading? What are you intending to do with that data?
Are you trying to determine if/when you need to pit to refuel?
Are you putting in telemetry so that you have access to this data in the pit?
Since there are many challenges with trying to get an accurate physical reading, I would consider approximating the fuel consumption.
Keep a running of of the throttle positions in small time slices.
Assign a fuel used number for each throttle position, small amount at low throttle, large amount at fuel throttle.
Add those numbers.
Multiple by a factor to adjust for real word measurements.
Then adjust that multiplication factor over several runs, where you compare the estimated fuel used to the actual fuel used.
Possibly adjust the assignment of fuel used at various throttle positions.
The advantage of this is that there will be no physical change to the fuel system.