No over flow on any C-body until...1972?
You can by those on the net. That isn't original to the car. but they are handy in the hotter climates. My 70' has one like it, but 68's didn't.
have this one from a 74 fury $20.plus the rideView attachment 41593View attachment 41594
I like that one. I prefer to use OEM Mopar style units whenever possible. ;)
I used one from an 84 pickup in my 300.