In a '70 240Z with a 4-speed the stick does not seem to move in a typical H pattern. Instead you are able to move it nearly anywhere you want to. So what's wrong and how do you fix it?

It's still an H patern, but it a very tired and loose. The shifter bushing are most likely worn out and require replacing. I recommend you purchase a factory manual or a Haynes manual and conduct a little research on the subject.

The early A model trans has what is commonly called a "monkey motion" linkage. It is not as good as the later linkage which was part of the transmission case.

You can still get the solid aluminum bushings for the early A model, but it still won't be quite as slick as the later B model.

Not only are that, but there are a couple pins that could possibly need replacing as well, they are held in place by "C" clips if I remember right, similar to how the later stick is held in place. You might be able to do some work there that will get rid of a little more play.