We've moved a lot of servers around using their frame's caster wheels, dollies, trucks, cranes, ... with all the disks in place - when powered off, the disk-heads are firmly parked out of harm's way. I don't think there's really a need to remove/bubblewrap all the individual disks. IBM doesn't do that as a rule on delivery of your servers (not in EMEA). Only reason I can think of is weight/height reduction on the big servers or SAN boxes (batteries and diskpacks delivered separately, tophat remove/replace).
Only problem (as stated earlier) is that some disks may fail to spin up after power off, but that can happen even without physically moving a server... So a backup is your best bet.
It is a good idea though to alter IBM of your planned relocation. They may have other ideas and may want to run a healthcheck on the machine before you move it.
HTH,
p5wizard