timber67 : This is just another good example of the many discrepancies, contradictions and questions which arise due to all of the changes made during the 1967 Model year. Note on the picture that you Posted from the 1967 Engine Assembly Manual in your Reply # 4, and the picture I Posted from the Electrical Assembly Manual in regard to your other Topic on the A/C Clutches (both pictures I have re-Posted here ; the Date on the drawing that you Posted (which shows the tube), is February 10, 1967, while the one I Posted (without the tube) is Dated January 1, 1967, a little over a month earlier. I have also attached three other drawings from the Engine Assembly Manual that show various combinations of Heater, A/C and Thermactor. Again, note the Dates.
Of course the best way to know what was actually used and when, is to find original, un-restored examples from each Plant, with Dates close to the one in question. This is easier said than done.
The above is just to give you an idea as to how daunting a single question can be, particularly for 67's.
Bob