Help with Rocks (or some form of clustering) install on existing infrastructure?

[scott-DPNOqEs/LNQ at public.gmane.org (Scott R. Ehrlich)]

I have an isolated LAN I'd like to get Rocks installed on, comprised of out of 
box systems:

- RHEL 5.0 64-bit (possibly to become the head node)

- CentOS 5.2 64-bit


According to the install documentation that I've read for Rocks 5.1, everything 
seems to point to building a machine from scratch.  Is it possible to add Rocks 
to an existing, production setup?  If so, what is the best way to do so?

Thanks.

Scott