kick down switch

I have gone back into the archives and have read some posts regarding this switch for `68-`69. it is different than the rest and almost impossible to find used. For those of you that may have used the switch for the later `70 -`78 cars , what was your experience? Modifications to the part or the accelerator rod? did it work? it`s not big investment for the part , i just would like to know what I`m up against before i tackle the project.