Brian, good info on the ball and set screw, always learning something.
I spent some tome looking at both shift balls, the OEM one for my non console 66 and the black steel on I am using on my 67, with the T lift handle conversion to Hurst shifter, Dan I see what you mean buy the depth of the steel knob, but for my use it will not matter, the T lift will not be used, only for looks on the Hurst shifter.
Here are some pictures of the two shift balls and measurements. the Allen screw is 5/32.