How did you split the distribution into 240k files?
Newer BSD based systems have a -b option to split that allows them to split files on arbitrary byte boundaries.
Here is an example from /usr/src/Makefile.
bin-tarball: (cd ${DISTDIR}; \ tar cf - . \ gzip --no-name -9 -c | \ split -b 240640 - \ ${RELEASEDIR}/tarballs/bindist/bin_tgz.)