I have a VPI Aries2/JMW 10.5 arm with a Lyra Delos cartridge, which weighs in at 7.3 g. I am quite sure you won’t need any additional weight on the arm because I still have quite a bit of tail left on my arm to extend the counterweight out to accommodate a heavier cartridge.
Of course you can always give VPI a ring and they'll be happy to answer your question if in doubt.