NEWER MODEL JOINTERS HAVE CHANGED OVER TO A SMALLER CUTTING DIAMETER. Measure your outer diameter with blades and it should be 2.480" or 63 mm.  Around 2004 Powematic changed to a smaller head. The older heads measured around 2.625".

63mmCC 6.003"CL 9.405"OAL SHELIX

Comes with new Bearings, now is the time to change them.