Design error! I should have modeled the pulleys and made the spindle mounting plate to get the correct center distance. I made it work but I had to sleeve one of the pulleys and add set screws.
The other issue is that the brake shaft needs to come up and the ballscrew shaft needs to come down. They will not line up as designed. So I will have to machine pockets into the underside top plate of the Z and in the top of the ballscrew mount.