What year car was the picture? It looks like a 66 style PS pump. The year may or may not be relevant to the discussion.The long tube had to come from another application besides Mustang based on where I and others have sourced the parts in the past.
Agree that the Mustang/Shelby style was used on other models and have seen them also but in our hunt for parts I think most of us in years gone by focused on part than the particular other details of the car I know I did. Time was limited, hot nasty days, more cars to sift through and so on
These particular pictures were grabbed off the internet - simple Duck Duck Go image searches for 428 smog big body styles. These may be 66's or a mix. Found others but like most forums people don't always post the identification of each car as closely as we would like. Ignored pictures that were reported to be restored back to original.
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Looking at an early 68 MPC and focusing just on 1967, I found the drivers side manifold listed as C7ZZ-9B445-A
This manifold was listed as used on:
Mustang/Fairlane (390) There is a revision manifold listed but the change is listed as 6 months after 67 production ended.
C7SZ-9B445-A manifold was listed as used on:
Passenger side - Mustang/Fairlane (390)
Drivers side - T-Birds (390/428) - big Ford from 9/1/66 (390/428 PI) - Mustang/Fairlane (390)
Seems to suggest/confirm Fairlanes were the other sources as well as Cougars/Cyclones and such of course