Hi Tadjou,

My old Direct Connection manual says that's a '70-74 1"x23 spline piece.
Unless someone has started repopping them, the gear internals for the A833
haven't been made in decades.  The last set of new parts I bought (in the
80s) were synchronizer assemblies that came in boxes marked "AutoGear".
They didn't slide worth a darn due to burrs on the hub.  My machinist says
that, as parts were inspected, anything that didn't meet specification was
tossed into a bin.  Rather than pitch them into the trash, Chrysler would
sell them to the aftermarket.  Aftermarket resellers would just put the
parts in their boxes w/o any work.  Watch out for "new" parts that aren't in
MoPar packages!

One or more of these folks may have what you need, or point you in the right
direction:
Liberty's Gears (http://www.libertysgears.com/)
Layson's (http://www.laysons.com/)
Bob Mazzolini (http://www.bobmazzoliniracing.com/)
Mancini Racing (http://www.manciniracing.com/)
Jim's Auto Parts (http://www.jimsautoparts.com/)

Though the synchro teeth on a Drive Pinion gear are used only when engaging
4th, they could still be hammered.  I believe Liberty's can cut the old
teeth off and weld on a new set on an otherwise-usable part.

Bryan