Spectra fuel sending unit

Imho the A 100 sender is no better than the other aftermarket.
Product Review: A100 Fuel Sender For 67 Dart

Look at the graph at the end of the post, the red diamonds are the resistance the sender wants at a particular level, the graphs of the senders represents the resistance provided by each sender at a particular fuel tank level, the late model oem unit is almost correct the others are too liner.