I haven't had any problem putting the sender with the capillary tube where the sender with the wire terminal came from -- AFAIK, the threads are the same throughout the entire B18/20 range, even the last two years when most of the motor went metric.

What is different is the heater tube from the back of the head. These come in several orientations, and while it supposed to be possible to turn it, I've always been scared to try it. A little creative work with heater hose and perhaps a 90-degree elbow (local plumbing store) has always worked out well for me.