Fuel tank sending unit

I had this problem with another car I have, 1965 non-Mopar. The unit went and I bought another, it was a re-pop, cost about $50, would only read half full when full, took it back, they replaced it, same problem. Then I got one that cost more than 3 times as much, I don't think it was NOS but it may have been. I think it was just a high quality re-pop. Anyway, works perfectly. You may be having the same issue, cheap crap re-pop unit.