raid0 - move a partition to a new drive?

[Peter Sebastian Masny <ps-list@masny.dk>]

Hi all, not really a Debian question, but you guys seem to know everything...

I have a software RAID0 array of three disks.  Two of them are full-disk 
partitions on identical 120GB drives, and the third is a 120GB partition on a 
larger disk.  I now have a third 120GB (same model as the other two) and want 
to move the partition from the larger drive to the third identical one.  The 
head size of the larger drive(255) is different than for the smaller 
ones(16), and its partition is a few MB larger as a result.

How can I move the partition on the larger drive onto the new smaller one? 

Is there a way to copy the partition? Remember the larger partition is a few 
MB bigger than the small ones.  I think a dd might possibly work anyway, as 
it would copy the main blocks, and leave out the trailing unused blocks, but 
I suspect that in real life this solution would freak out the raid system.

I don't have an extra 250 GB available for copy-off-copy-back.

Thanks,

Peter