Hey Greg,
I've done that modification to my '64. I used the ball stud that threads into the block and mounted it to some heavy flat stock. I used a couple of bolt holes in the side of the block to attach the flat stock and then lined up the Z bar to locate where the ball stud goes. Drill a hole and put a nut on the back of the ball and you're done. Hope I didn't confuse you. I did this quite a few years ago, so the details are a little fuzzy,
Scott
