I can't remember. 2 blades, though. :-)
I found a digital pic of our logbook from 1968 for an engine overhaul that
says it had a Sensenich. Not sure if that's what's still on it or not. A
friend of mine has an '65 or '66 180. He has the red arc, too.

"Greg Esres" wrote in message
...
Perhaps in a tach from a plane that had this prop, or the Archer
actually has it.

The owner is unaware of any such installation for this airplane, and
there is no supplement in the POH.

What prop do you have?