The 03268 is probably a machine shop's identification stamp of their job number. That would indicate that the motor has been rebuilt. See if you can spot the same number on the opposite head. It may be at the back of the motor right next to the distributor, and you would need a mirror to see it.
On the center two exhaust ports should be a cast-in "47" which would be correct for a '69 350 2-Bbl.
