Problem installing postgresql 7.3.6 on Redhat 7.3

Dear group,
                      I would like to know where I could find rpms for
Redhat 7.3.  I have looked at the downloads page and I see only source
rpms and rpms for Redhat 9 and FC1.  I did download the src rpm and when
I run the rpm -ba postgresql.spec I get the following error message:

configure: error: could not find function 'krb5_encrypt' required for
Kerberos 5
error: Bad exit status from /var/tmp/rpm-tmp.93268 (%build)


RPM build errors:
    Bad exit status from /var/tmp/rpm-tmp.93268 (%build)

How do I get over this.

Regards,
Shan.