[CentOS] Question on installing 2.6.18

Hi,

I have a need to install 2.6.18 kernel.

After I configure, make, make modules, make install (all that is good).
The last thing I do is 'make install'. This also modifies grub.conf and
adds an entry for my new kernel. However it leaves the old kernel as still
the default. Is there a way to have it automatically set my new kernel
as the default in grub.conf so when I reboot the new kernel is active.

Thanks,

Jerry