Non Rallye fuel gauge either full or empty

Two questions... What model you working on? What resistance did your sender show near the center of its sweep/travel?
Calculator says half way between 80 and 10 is 45. That isn't what a chrysler gauge is looking for. 23 ohms is half of this gauge needle travel. 45 ohms isn't empty though. 45 ohms should be a bit above empty, approx' 1/8 tank.