Something you will quickly notice about piper products is the fact that, they all are truly part of the same family of aircraft. Like most cessna single engine aircraft.

I'm not surprised in the least that they share the same airframe, but he same airfoil is a little surprising to me, at least.

I have my trusty warrior POH, so that wont be a problem. Looks to me to be NACA 0009. Now hum:

http://naca.larc.nasa.gov/reports/1940/naca-tn-761/
http://naca.larc.nasa.gov/reports/1938/naca-tn-633/

And then the hollygrail of things (links)

http://www.albacore.org/usa/images/naca09.gif

Ah too quick.. Foudn a better one

http://www.engr.utk.edu/~rbond/N0009.pdf