I did a search and there's a lot of threads on how to replace the bushings, but my problem is how people are getting the darned nut off at the bottom of the shifter rod. That thing is now fused to the circular rod, and i can't pull out the shifter and replace the bushings with it on there.

Any ideas? I heard mention that there is a 14mm flat spot but i don't see it ANYWHERE. Do I have to obliterate the old rubber bushings to find it?

it should have a "C" clip on one end of the pin. you should be able to pull the clip and slide the pin out.

Kinda confused by the "Nut" thing.

you're thinking of the shifter PIN bushing. I'm talking about the regular bushings that hold the neck of the shifter. There's a nut at the bottom that squeezes is all together, and I can't get it off.

The flats are just above the bushings on the shift lever. The drawings don't show them, so I added an arrow.

This is the A tranny, which has the same linkage as the Datsun Roadster. On my roadster I used a 14mm wrench to hold the nut, (accessed from above) and turned the shift lever by the flats, as referenced above. I'm not sure if you access the nut on the Z from above or below, but the mechanism is the same.