The tach has it's own option code, N85 IIRC.
The vacuum gauge also has it's own code.
I have never seen a tach-delete code.
Since 1970, I've almost always had 4-speed rally-dash car and every one had a code N85 tach.
However, the tach is in the wrong spot, is too small, and is usually if not always, too slow. So I usually replace it with the vacuum gauge, which, as the cam gets bigger, needs to be damped........ cuz otherwise, it's too fast ...... lol.
