Is there different pitman arms for 1972

Yup, that hole in the steering shaft you mention is also up when v notch us up.

So something I have figured out with research late into the night is that the pitman arm seems to have 4 wide master teeth spaced 90 degrees apart. Does this mean the pitman arm can go on the gearbox in a multitude of orientations that could be wrong to position the steering wheel correct?

Maybe the wheel is on wrong. Yes there is 4 master splines, but only one correct way to have the pitman on.