camarojoe said:
I think its a really poor photo of a 66 chevelle.
Yes, it an early ignition coil. What's shown in the picture is also know as a vibrating coil. On a "regular" coil the supply voltage must be cut off (like points used to do) so the field collapses and there is output on the secondary side of the coil. These vibrating coils produce a constant spark, almost like a transformer.
Some guys look for these if putting flamethrowers on the exhaust. It's the easiest way to keep a spark going on the sparkplug.