Pistol out and round ball in?

Yes you can just pull the pistol grip out and put the ball shifter in..

Now, just to be perfectly clear.....You are referring to the handles only, right? (I don't want to buy a round ball handle and then find out I need a different mechanism.)

In my post #7, I was not thinking of replacing the mechanism. I just wanted to make the point that the slip-in style mechanism was applicable to 68-71 A and B body cars. So, it should not matter whether the 2nd owner changed the mechanism or not, right?