Moving foruns - changing hierarchy

Hello,
I will update my site and I need to move almost all my forums to a new category to be created. Of course I will create new category to the new forums. My question is whether indexing in search engines, Google in particular, will suffer some damage with this movement of forums.

Thanks

joao barroca
aka beduino

Your threads will automatically 301 to the correct location, however, you may take a hit.