how to (r)sync group-ownerships?


I just moved a bunch of files from one system to another using tar/gzip.
Now after unpacking and modifying I realized that on a small number of files the group-ownership is wrong (some strange bug in tar/gzip I guess cause this didnt happen the first time).

So now I just want to sync (probably with rsync) the group-ownerships, *but not the filecontent itself*, cause some of the files have already been altered on the new system and shall not be overwritten !!

How can I do this?

thnx
peter
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