I just tested 3 of the white and 4 of the black a couple days ago using my RPM test rig.

NSR shown for example only.
The white and black are virtually the same. In fact one white endbell had a 500K advantage.
They all tack out higher than 21K with the average around 23K.
But you can always get a dud. I would just have them swap it for you. I have had one myself, but that's out of a very large amount.