Something seems amiss as the Vin stamping indicates '65 Coupe VIN 194375S224388 or Roadster VIN 194675S224388 which would be waaay beyond actual production?.
Perhaps check your #'s again as 65 'Vette production ended w/ sequential VIN # S123562..
Also is there no plant digit in the engine build date code...Flint or other?.
~ Pete