[unruhjonny]

iirc the four speed supplier change had nothing to do with model, but everything to do with model year;
I am pretty confident that a 1973 Grand Am with a four speed would have a muncie.
If it was a late 1974 car, then it would likely have a BW ST-10.
If it was a 350-2bbl, it would probably be a saginaw.

It’s a Pontiac, so it should have a (factory) hurst shifter.
That’s probably an i credibly rare shifter arm - as it would be 1973-75(?) Pontiac specific;
Likely shared between Grand Am’s, (1973) GTO’s, and Lemans’.