This pertains mostly to the 3 cylinder (152, 164, 179), and 4 cylinder (202, 219, 239) engines. These cylinder blocks can have the same casting numbers. Use this chart to identifying what engine you actually have.
John Deere 300 Series Sleeve Flange Measurements
The above measurements are the measurements of the actual sleeve flange. When measuring the block, the measurement may be slightly bigger. These measurements are used to determine what size engine block you have. Please use the figure below as a reference on how to measure.