[CentOS] How to configure PAM in Centos 5 64-bit?

Tue Jul 3 22:01:05 UTC 2007
Scott Ehrlich <scott at MIT.EDU>

I'm new the the PAM world and have CentOS 5 64-bit installed on a system.
I want to tweak some of the system-auth module settings, but the top of 
the file says anything configured in that file will get overwritten, as it 
is autogenerated by authconfig.

I checked out authconfig, and it doesn't seem clear to me how to make the 
changes I need via authconfig.

So, where do I need to look?   What utility/file do I touch?

Thanks.

Scott