[Andy Brockway]

If you want to modify a gear yourself or have a shop do it for you, then any stock gear with a 5/16" bore will work.

5/16" bore will work with an 8mm reamer. Ream the gear with an 8mm reamer and broach with a 2mm keyway broach. Add a set screw over the keyway if you want or use the retaining ring as used by AndyMark.