I believe that the one on the far right was used only in 1966, Ford casting number C6AE-9B453-B. 1967 Engine Assembly manual calls out this part for both, 240-6 and 390 engines.
The middle bracket (which is a modified version of the above bracket) has been found on an early (Sept 1966) S code Mustang. Documented by Tim Lea in an old post. Number stamped C6AE-9B453.
The C7AE-9B453 bracket (far left) has been mentioned in older posts as being correct for 1967. It does not show up in my MPC's, indicates "C6AE-9B453-B for 1966-67 390 and 289 with A/C".
It does appear in the 1967 engine assembly manual, Pages 120-121. Part number called out as C7AE-9B453-B.
*Note, also used on 289-2V and 289-4V with A/C
For installation on 1967 cars, anyone have a query of when the changeover may have occurred?
