What airfoil type is used on the B727-200F?
My favourite book for questions like this is Obert’s Aerodynamic Design of Transport Aircraft. It shows pressure distribution on the 727 wing and gives some AIAA papers as sources. If you track these down, that might reveal more. Unfortunately no airfoil reference is given; however it is very likely that the 727 uses a proprietary Boeing airfoil.

Posting as answer despite not really answering, as it is still more than a comment...