Every post here makes sense, especially regarding how people are inclined to buy CHEAP. I built my 70 Charger in 2003 and had a new gas tank and 3/8 sender shipped from Year One. At that time, I knew of no other fuel sender vendors other than The Paddock. I had to spend $ 160 for the sender only to find that at full tank it read 5/8. No dead spots, but it was slow to move from 5/8, then when it did, it fell FAST as if I just drilled a 2" hole into the tank. What a piece of crap. Being a Mopar guy has always seemed like we have to improvise/adapt and overcome.I don't know how many times that I have said to myself that " I MUST really love these cars to put up with this kind of stuff."

I don't think anybody calibrates these gas tank senders. They should be checked for a certain resistance at 10 different positions to make sure they are accurate. One of the problems is the winding of the wire resistor. The wire inside a factory original is not linear. They wind the wire closer together at one end to match the rate of drop of the float. This keeps the gauge reading to match the shape of the tank and float arm angle. The last sender that I took apart that was a repro was not made this way, the resistance wire was wound evenly down the whole length.