Generally speaking all 68 Mustangs with manual transmission came with a tach (includes 3-speeds and 4-speeds). I am not going to say because as soon as I do, someone will say that they have an "oroginal" 68 manual transmission Mustang without a tach.
The only tach for Mustangs in 68 is the 8K tach.
Regards,
Pete Morgan
Pete,
Respectfully, I gotta wave the BS flag on that statement. Marti's Mustang By the Numbers book has 8,147 tachs in 1968, and there were 28,073 3 speeds just for the 289 2V engine. Now then, there were 3,858 2892v, 3 F2v, 5800 S codes and 1616 R Codes, all 4 speeds. There are even more 4 speed manuals than tachs.
Randy