Mine are a couple of years old and are numbered – 4170 171004487.
Same number; different prefix.  My guess is these number are some sort of manufacturing batch and/or sequence number, and have nothing to do with flow rate, and any 2013 injector should give the same flow.

Thanks for checking Al.  I agree about the prefix number.  I didn't figure it was important, but the long 17x number is the Rochester part number.  Odd that they would change the part number for the same injector.  Don't get me wrong, I fully expect that the new pair will work exactly the same as the old ones, but I can always hope.  

Rusty