Orig(most Popular #69730= about 22.8-23.4 cc. or Ml....... Same Thing; Yes they are because I know someone's going to say there different 60363 tend to run a little larger23-24.4, I do these heads for Preds. Daily and have 26 sitting here as we Breathe
Nox is a major factor, not just HC emissions.
I wouldn't be suprised to see the combustion chamber volume increasing along with the the bigger bore and stroke.
People are throwing a lot of numbers around however....