From the 67 Plymouth Dealer order book the Formula S package details.
Also a 67 dealer quick options guide (2 pages). 2nd page I've digitally highlighted the tach and Vacuum (Performance Indicator) gauge options.
Side note to QWKSLVR, interestingly this doesn't show the "clock" being an option on where I would think would be on page one. I know they were and are on the dealer options lists for 68 and 69, could have been a later option or 68 or 69 model year only?