Not sure what it's called - the round green plastic thing that has the post that the horn connects to and the copper track that contacts the turn signal switch. I managed to break the post off of mine.
I assume it's the same for all the standardized columns (66 and up??) but mine is a '72.

Thanks!

 

Are u talking about white plastic turn signaling cam? Do you have a tilt wheel? Send us a picture...

 

Turn signal cancel (canceling) cam!
Found a bunch on eBay. Lots of part numbers and the application data varies wildly. Got one on the way that may be for 68-80, or may be for 76-82. Who knows.

 

Nice I got the part GM number off mine and bought a new one too, its the same GM part number for a 65 Corvette with tilt wheel