I had the opposite problem with my Grado Reference Cartridge.I had it tracking at one point way over spec. at 2.6 grams with my Morch Arm.I realised this when I bought the Shure Precision Stylus Force Gauge SFG-2.
In my case my arm comes with 3 different counter weights
so I was able thru trial and error finally able to get it tracking at about 1.6 grams.I had on to large of a counter weight to begin with,and used my medium and small counterweight to balance things out.
My weights are a bit forward closer to the pivot ,But everything is working fine with my VPI MK3 Morch UP-4 Combo.
I'm not familiar with your arm.Do you have the option of using a heavier counterweight?Your cartridge weighs the same as mine so this may help alot.If not 1 or 2 small lead spacers between headshell and cartridge should help.