The one-piece UJ AHH6000Z has a different clamp bolt spacing of 1/4" less (1/8" per end) than the original UJ so I drilled and tapped (M5) a new hole at 'B', the original CB hole is at 'A'. Photoshopped to remove the parallax error, pencil in the clamp-bolt hole:
The shorter clamp bolt spacing brings the centre of the UJ closer to the rack by 1/8", so as well as the column shaft having to move down through the outer 1/4" (1/8" for each half of the UJ) to meet the rack shaft the angle between the two shafts is also altered, which is why realignment is advisable:
The same effect could be achieved by angling the rack shaft upwards and just using the movement of the column inner within the outer for the two clamp bolts to be inserted. But as well as altering the alignment of the column being easier than altering the rack (which has no scope for moving that closer to the column shaft), the column and wheel would still be further away from the driver, which may need the column outer to be moved further away as well so the wheel doesn't foul the cowl, so alignment would still need rechecking.
Column removed, showing the later bulkhead seal. This was necessary because I found it impossible to slide the column in the U-clamps while they were in the dash brackets, even with the bolts slackened right off:
You can just see that the rack shaft splines protrude inside the UJ by about 1/8" whereas the column shaft protrudes by about 3/8". If it was pulled back by 1/4" and a new notch drilled then the steering wheel to cowl relationship should still be the same, but you should still check the alignment as the centre of the UJ is now lower than it was originally, and may well have been incorrect before you started if you are changing the UJ because the old one had worn!
The one-piece is much slimmer than the original (no wiring on the hydraulic brake-light switch as I have converted to a mechanical switch):
