Are you copying or renaming? If you're just renaming, then yes, just make
sure that you mv both the BRIK and HEAD files to new files with the same
filename, since that's all that 3drename does.
If you actually mean to copy them, then the 3dcopy program also assigns
a new unique ID code in the new HEAD file. You can use the 3dnewid
command to fix that, if you choose to copy by hand, and again, don't
forget to copy both the BRIK and HEAD files.