Greg Esres wrote:
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?

It's not just the prop. It's the prop/engine combination. The
Cherokee "C" model 180s and earlier had a hollow crankshaft that caused
some harmonic vibrations between 2150 and 2350. The Archer may have
inherited an airspeed indicator from one of those earlier planes.
Beginning with the '68 "D" model, the 180 hp PA28s were equipped with
the Lyc. O-360-A4x engine, which had a solid crankshaft. This removed
the rpm restriction. The Archer in question should not have any rpm
restrictions (except at 2700), if it is equipped with the factory model
engine and prop.

John Galban=====N4BQ (PA28-180)