The 608's stretch back at least until the early 60's, Corvettes included - and up until the short pumps ran out of applications (the last being truck applications). No dates could be an omission during assembly, or late production - the other (generation ?) or mold number on the pump might help weigh that out. The '67 dated Flint pump I bought has a low GM casting code compared to the '68, '69 an '70 pumps I've looked at -
If you haven't done so, add the part number to your saved searches on eBay, and it will notify you every time a new one is added to the list. Keep looking, and you're liable to find one fairly quickly. Or contact Bill Mock mockauto.com), he probably has more than several ready to go in stock in your date range. Lifetime warranty, rebuilt properly. Check out his website -
Regards,
Steve