Report Conversion from square to round headlights in 1963-64 Avanti Posted Tuesday at 11:51 PM That's currently a touch over $1600 US and if he has the correct front valance the entire structure across the front of the car will need to be replaced. Difficulty is the entire front needs to be removed properly, joint strips fabricated to join the new and old panels and the entire valence assembly aligned and re-adhered into position. There's a lot of fiddly involved to get it right but far from impossible. Not cheap to farm out either. Parts prices are in-line if they are new or in excellent condition. Some of those parts are also not so easy to find and having everything could save a lot of time and hunting. Get the parts manual if you decide to go for it and be sure everything is really there. IMO the round eyed ones are the best looking and I considered doing the same thing to my 74 but it needed so much other work that I never got around to it. If it's your dream, go for it.