Does anyone have access to a sending unit for a 20 gallon that they can measure? I'd like to know the distance from the mounting plate to the lower end of the pickup tube. I've read Spieg's thread https://www.cj-8.com/threads/how-deep-is-a-factory-20-gal-tank.48189/ and others on the net concerning tank depth. I'm goint to add the Speedhut sensor and would like to cordinate empty with the lower end of the pickup tube, not the bottom of the tank. Anyone have a shelf unit they could put a tape to?