I would like to double check my manual. manual says 21 13/16... but is says long shaft. This number seems too long as I am have the adjuster on only about 1/4" of the threads.
My '74 factory manual says thread it all the way on, then a turn and a half off, but that it's not critical. I think it's critical on the post-1977 all-mechanical units, and not an issue on the 1973-77 mechanical/hydro units.
