You can download older and newer versions by replaceing
the "7.3" in the suse-ftp address by 7.2, 7.1, 7.0, 6.3, 6.2 ..
or the newest 8.0.
If your GLX package AND the nvidia kernel package (same version
number is required) are the correct ones, look at any error messages
when X is trying to start. Install according to the README file located
in the GLX package.
How old is your Redhat 7.3 distribution?
i'm running suse-linux here, an older 6.3 (i think from 1999)
with kernel 2.2.13 and 8.0 (2002) Kernel 2.4.18 and Xfree 4.0.
I'm sorry no experience with Redhat 7.3 :-(
I've read about it, not tested as yet, however it should work.
If you are connected to ftp.redhat.com you can do a RPM search,
in your case 3ddiag by entering
" site exec locate 3ddiag "
The system should display the location, or locations.
The 3ddiag-package contains diagnostic tools for the basic graphics
driver and system libraries and its configuration on the system,
written by a man called Stefan Dirsch. It has a GNU
General Public license.