This is correct from my experience. I recently tried to rebuild my v1 B44.2 shocks with X-rings, and found that they leak profusely. I talked to Chad Due at the track that day, and he said that the old and new shocks have a difference of a few hundredths, which is enough to make the x-rings not work in the old shocks. I rebuilt using the red orings and all was back to good.