Through those 3 years, the interior didnt really change much, arm rest pads were slightly different. 67 had round radio knobs, while 68 and 69 were thumbwheel, so the instrument bezel had different cutouts for the radio. There was a thread on here that told me 67 was 1 year only for the pitman arm. As for the formula s version, it had rallye dash, upgraded suspension, extra badging, for 68,69 the engines were 340 or 383. Not sure of what engines were in the "S" for 67, I believe 273.
