Larry, the casting date is a raised casting on the pass. side of the block above the starter. It is not a number stamped on the block surface. should look somthing like this.
C 3 0 or B 18 3
Hope this helps
"If it ain't Steel it ain't Real" "Earth the insane aslyum for the rest of the Universe" 41 1/2-ton, a work in progress 68 Shortbed stepside 327/325hp/700R4