As someone that owns a 67 conv 383 4 speed formula s I’ll give my two cents for what it’s worth. I’d say that if you could buy that 67 blue 383 4 speed posted previously and it is as nice as it looks inside and out and mechanically, high teens is an absolute steal. Most cars you see advertised as a true bb 4 speed a body are not correct. Even if the car is not restored but mostly rust free and complete and mechanically sound it is a rarity. Almost every real bb 4 speed a body that you see advertised unless a concourse resto is missing many key parts like radiator, fanshroud, oil pan, manifolds, correct carburetor, intake etc. All those things cost big money today. Also believe it or not there is quite price difference between the same year bb a body auto and 4 speed car. Often people throw around numbers of what they think the car is worth but truly the market decides and I’ll tell you most cars are not complete or done right so a survivor that is complete and even with wear and patina is often worth more than you think. Avg market values and being able to buy a real car that is complete and correct is a big difference. Example my car a complete mostly original car with one repaint in 1991 is one of 9 or 12 made in 67 depending on different sources. Therefore the mkt value may say $35,000-$40,000. I say the problem is finding a nice one to actually buy. That is where the difficulty comes into play. To actually find one and buy may be quite a bit more. How bad does someone want it? The opportunity may not come along again?
Carl