I've had some helpful tips about this topic already; but the options unfortunately are a steep climb as I've found. First has anyone done this sort of modification? I just came across a Mustang site where headrests were installed on a '66 Stang thanks to an outfit that makes a conversion kit complete with a nifty ratchet forward/back adjust. Of course upgrade parts for Stangs are everywhere unlike pre-66 Mopars. My guess roughly is that the later models, like the 68-70 seats, didn't change much dimensionally but the adjustable style headrest was added having a dual slide rod and rectangular or semi-oval shape padded rest. This maybe being the case, doesn't make for an odd addition to my '63 Fury buckets. They would look a little later "factory" Mopar is about all; so I hope. My interest is mainly for safety since I've had a partial neck fusion and want to avoid a whiplash injury with all the maniacs on the road. I've sent a message to Legendary Interiors for possible help as they did the interior for me some years back. If anyone has some experience with this would appreciate the advice.