built for Centos 4, source from RHEL RHCS/RHGFS rpms in
ftp.redhat.com/pub/redhat/linux/enterprise/os/RH{CS|GFS}
kernel related rpms are built against i686 only.
http://chantaipo.cjb.net:8080/pub/centos/4/RH{CS|GFS}/i386
only up2date works at the moment if you want to try them out.