In a previous Post from 2019, Bob Gaines replied as follows :
"The 390 typically got the short column with a rag joint coupler regardless of if early or late production . It was the smaller displacement engine cars that got the long version column until the changeover to for all cars to the rag joint shorter style regardless of displacement happened in May of 67."
Bob's use of the word "typically" implies that there may have been exceptions, but in general, Mustangs with the 390 had the rag joint with the short shaft steering box.
As for the "May 1967" date, there wasn't any documentation given, so one must assume that it is based on his hundreds of observations.
I have looked in the 1967 Parts and Accessories Catalog, the 1960-68 MPC, the 1965-72 MPC, and every Technical Service Bulletin, page by page, from December 1966 through September of 1967, and none of those references give any date as to the change from the long shaft to the short shaft with the rag joint.
My January 31, 1967 Dearborn built 67 with Factory PS has the long shaft with no rag joint.
In summary, until more exact information is found, May 1967 appears to be when the change was made.
Bob
