So I am using pigz in tar with
tar --use-compress-program=pigz
and this works but it doesn't use all of my processors, and I'd like to make sure it's recursive (-r) and using (-9 compression level).
I read through Utilizing multi core for tar+gzip/bzip compression/decompression but it doesn't note anywhere to add additional commands in that format, and I couldn't find anything in the man page for either program for additional swithed.
Thanks, Cam
Mark Adler's top voted answer on the SO link that you included in your question does provide a solution for specifying compression-level as well as number of processors to use:
tar cf - paths-to-archive | pigz -9 -p 32 > archive.tar.gz