I bought 2 pairs of yellow rx8 injectors from 2 different sources for my miata. Are they all the same spec?

One is Denso X and one is Denso Z. Denso X and Z say 195500-4450 on both injectors.
Denso X has the numbers 526 printed in a spot and 21 elsewhere.
Denso Z has the numbers 326 printed in a spot and 17 elsewhere.

Are they compatible between eachother what is the difference?



Thinking of getting them flow tested and see what they flow and how they compare.

thanks

 

maybe a serial number from mazda etc they are 425 cc high ohm injectors though.