You can download the the src.rpm of the tar version and install that. It will install in /usr/src/redhat and in there it will place the tar file it was using in its build. and in SPEC is the spec file it used to build. Open the spec file in there and edit the file name to the new archived name of the new tar file you wish to build. In basic you modify the spec file for tar in SPEC directory to point to the new archived tar file. Place the new tar archive file in SOURCE directory. Then build the rpm and see if it works. May need to tweak other spec options.
Install the the latest tar*.src.rpm from a Fedora mirror.
rpm -ivh tar*.src.rpm
Copy the new tar archive to /usr/src/redhat/SOURCE
Then modify the spec file in /usr/src/redhat/SPEC to reflect the name of the new tar file.
Then to build the rpm use this command.
rpmbuild -ba name_of_spec_file.spec
If it completes with no errors then the new rpm will be in /usr/src/redhat/RPMS
Or goto here and get the one from the development directory. Not sure if it will install or not because it may require newer rpm depenencies. You may download the src.rpm of that version and build it on your system using current system specs. To do so use this command to build.
rpmbuild --recompile --rebuild full_name_of_tar_src.rpm