Vibration issues

So if I understand correctly..

1. You had a vibration
2. You replaced the center section
3. You had a vibratation.
4. You lost a driveshaft
5. You rebuilt the driveshaft
6. You replaced the center section with the previous center section
7. You had a vibration.

Have you.

1. Put the rear end of car up on jacks, with engine running and in gear and brought it up to vibration speed
2. Had the tires balanced
3. Checked that the vibration is not present when not in gear but at the same rpm
4. Checked your axles for streightness
5. Any chips on the brake drums
6. Proven it is not the transmission
7. Trans and engine mounts intact and bolted down propperly
8. Previous poster pointed to pinion angle, did you change that
9. Shock absorbers good