2" on a GC 1 or 2. Instead of using a tape measure to check the frame height, all you need to do is screw all the leg levelers up all the way, set the table, then adjust the 3 low legs to be at the same level as the highest leg....is that so complicated that you need to go around measuring each corner? In a perfect world the floor is flat, but in most cases its not, so measuring the height of the corners of the frame is a waste of time, adjusting the 3 levelers to make the rest of the frame level with the highest lag has nothing to do with measuring the frame height. And think about it, if all the levers are screwed all the way up.....every corner of the frame will have the same height measurement.....right?....but the frame still won't be level, until you adjust the feet, which then in turn changes the frame measurements to the floor...right.