My 71 parts book only shows 2 part numbers. One for car 3420849 and one for station wagon 3420850. Police has a special section and it calls for the part number 3621608 as you listed. I checked parts voice and none showed up.

I have a volare that has a two model year only sending unit that is hard to find. I was thinking of removing the gauge portion of a nos sending unit and switching it with the old one. I wonder if anyone has done that before? I can`t remember how it is attached to the tube.