You should take this to the Bicycle Mechanics forum. You don't preload a threadless headset to a specific torque, but you do tighten the stem bolts to a torque. 9-10 Nm is hellaciously tight for stem bolts. I fear you will crush your steerer at that torque. Normally those bolts are not tightened to more than 5-6 Nm in my experience. Could you be looking at the torque for setting the expander plug inside the steerer? Though that seems awfully tight for that as well. Please get some expert advice before proceeding.