<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">...Could the dates be so close because the car was built at the Pontiac plant?... </div></BLOCKQUOTE>
YES, the foundry & engine assembly plant was @ Pontiac, MI, & it makes sense that tighter dated engines would show up in Pontiac plant built cars. In looking at a calendar of 1969
http://www.flicklives.com/Timeline/1969_cal.html
Oct 24th was on a Friday the 4th week of Oct, for a J249 block to end up in a 10D Pontiac body, the body would have to set in the body bank up until mid to late 10E... definitely possible.