Beginning with the indicator set at 0.050, rotate the crank 180 degrees to the opposite mark and measure the change. If the distance is smaller, the bellhousing needs to be lowered. If it is larger, the bellhousing needs to be raised. Repeat the process at the 3 and 9 o'clock marks. Your goal is to have the register bore centered over the crank centerline within 0.005 inch.