Here are some links that show the location of the engine casting numbers. (wider angle)
The date code that Tim is asking for is next to the starter. to the right of "CON 4"
http://www.langdonsstovebolt.com/wp-content/uploads/2014/01/55-57-235_22.jpg
http://www.langdonsstovebolt.com/wp-content/uploads/2014/01/235_261_50_TO_54_CASTING_NUMBER_PIC.jpg
http://www.langdonsstovebolt.com/wp-content/uploads/2014/01/235_261_58_TO_62_CASTING_NUMBER_PIC.jpg

The attached photo shows the location of the ESN = Engine Serial Number, to the left of the distributor.
The ESN is stamped into the flat machined boss using letters & numbers metal stamping dies. It is not cast into the block.

xfiles
Attachments
Engine ID cast numbers.jpg (92.56 KB, 226 downloads)