Thanks, Moses. I was thinking the previous owner had put a standard 15 gal sending unit/arm/float in the tank years ago (even though this Jeep has a 20 gallon tank), but I did not want to influence your answer, so I appreciate the detailed response with different things to check before I just drop the tank and replace a sending unit that I might not have to. That said, after checking everything, if I do need one, I have not heard great things out there about any of the CJ-7 sending units, much less the 20 gallon type. Any suggestions on where I could get an accurate one that is made well? Thanks, Howard