8 CMU Dimensions
seven 5/8 by seven 5/8 by seven 5/8
seven 5/8 by 7 5/8 by fifteen 5/8
eight by eight by eight
eight by eight by sixteen
Nominal dimensions: will be these found in stating the unit dimensions. They're corresponding to the actual required sizes along with the thickness of the mortar joints.
Actual dimension: is the actual calculated size of the unit.