NOTE - Moving the thread since it focuses on one particular year
Kind of a pain to find pictures since PS and AC was becoming more popular in 67
The small sender was used for the light (with tach) option
Confirming that the gauge used the bell style - here are some examples. As a side note this was the typical shape from what I can recall of the sending units seen in the 50's and early 60's Fords
Yes there are a few "creative" details in the pictures
Looking at the read reference it shows the following for replacements
SW-667 for the oil sender without tach and trip
SW-673 for oil sender with tach and trip
390 uses different sender
Did use the Cougar heading since the Mustang section of the book is a mess (unusable