correct gas cap for '66 Barracuda

Most were body color but they made some chrome ones too. They all had a straight, horizontal bar like 65 Dartman says above. Stant was the OEM but their replacements in the auto parts stores were different. The surface wasn't flat and they had a "S" shaped black handle. There were many companies that made a replacement back then but they all looked a little different. Look on e-bay and see how many different ones you can find! Some fit better than others too. I've seen some recent repops that look like the originals but I haven't bought one to see how they fit.