Is the mopar fuel sender part # 4051004 the correct non-linear sender?
Well, I ordered 4051004 from classiccarautoparts,
CHRYSTLER-DODGE-PLYMOUTH GAS TANK SENDING UNITS >>> Classic Car Auto Parts part # N-CR11, described as GAS TANK SENDING UNIT
1963-1976 Barracuda, Dart, Dart Sport, Demon, Duster, Scamp, Swinger, Valiant. Mopar New Old Stock, part no. 4051004. Line size 5/16". Number of lines: One. So guess what, same old linear aftermarket junk. I'll be trying to get my money back tomorrow. I did find this though, which the seller promises is a non-linear remake. I guess we'll see.
1963-1976 Chrysler A-BODY DART DUSTER 5/16 FUEL TANK SENDING UNIT FS4051004 | eBay