my opinion on balance shafts are this. Mitsubishi put them in there for a reason, and taking them out of a factory engine will do you more harm than good. if you have a need to remove them and want to scratch that itch, then you need to have the whole rotating assembly (crank,rods,pistons) of the motor fully balanced by a machine shop. that is the only "safe" way to remove the balance shafts and not destroy the motor long term