Would it not be more reliable to just use the Bisi block off plate and leave the shafts in the motor? In theory taking out the balance shafts will make the motor eat itself alive and create alot more internal vibrations. The horse power increase all be it very small will come from just removing the belts. Removing the shafts might gain another small increase but is it really worth it? Maybe it saves alot of whieght removing them? Im very curious about this as well. Picking up an H22 tomorrow.