1967-69 Disc brake tie rod adapters. For use when installing 1975-80 Granda, Monarch, Versailles spindle on 1967-69 Mustang inline 6, V8, (except boss), early falcon, and ranchero.
In plain English if you are using the horrid Granada set up on your car you will need these to reduce the taper for your track rod end {tie rod }
Throughout the years ford used lot types of tapers here are the most common Below
64/66 six cylinder
64/66 v8
64/66 v8 power steering
67/69
70/73