Steering column questions...

That's exactly what to do, move the shaft with box coupling from 74 column to 69 column. I'm not the only member who has been there done that. I would replace both bearings and might rebuild the box coupling while I'm at it. I had no idea the upper bearing in my 67 column was crusty and roared before I could spin the steering wheel at the workbench. Never noticed in use in the car.
My donor 73 power steering box coupling didn't have excessive wear but some... renewed it. All good for another 40 years.
You'll find another issue at 69 bumper mount/bolts to those later model frame rails but that's another thread.