Was there any particular sending unit that you used (as in from a certain car)? So, if I went to the parts store and wanted to buy a sending unit for the car, do I just pick some random car or do you know what yours is off of?
64-85 Dodge sending units for a gauge will all be the same. I just asked for a 69 Dodge Car with a gauge. If they bring one out with a threaded top where the wire goes, have them look at the pictures and get the one with the button type end. I got mine at my local Car Quest. You can also get them from DodgeBoy on Ebay for around $15.