Yes, the method 1 WILD RT suggested is what I have in mind. My reason for doing it is to determine if the block is square and if it has been cut. The 12" micrometer mentioned would be perfect, but I haven't been able to find one that size. I noticed that Harbor Freight has a 24" one, but it only measures in fractions or millimeters (no dial). I suppose I could convert a millimeter reading.