I agree with Mike. It is likely a 0-90 ohm sensor. That can be checked by filling the tank, disconnecting the leads to the sensor, and reading the resistance. Do the same with the tank near empty. That's pretty close to the full sensor range.

Also, the Gen5, CTS-V etc. fuel level sensors are 250 ohms empty, 40 ohms full. This assumes that the height range of the sensor is the same as the tank.