Here's an interesting and, not so unusual, contradictory listing in the 75 edition of Ford Car Parts (aka MPC), Section 30 page 22 (available in the Forum's Library):
The service stock number for 67 thru 70 manual steering is C7ZZ-3350-B (power is C7ZZ-3350-B), and for 71 on is D3OZ-3355-A (for M/S and P/S). At the bottom of the page is a note that pertains to 69 on:
"Attaching parts serviced in assy. only due to swagged bracket end".
That note implies the swagged/peened end was used from 1969 on and does not apply to 1967 and 1968, but the service replacement covers from 1967 thru 70.
Like I said, "contradictory".
Jim
Note: In every query regarding hardware, I research to add or correct the Mustang Hardware Spreadsheets. My original entries were based on the Mustang Assembly Manuals. If the hardware item was not listed in those manuals I "defaulted" to Ford Car Parts, only when the hardware item was questioned. As the are over 5500 pages to review, I declined to spend additional research time except for situations like this.