I was at the dragstrip today and saw another racer with a SHO. His was a 100% stock 2016 SHO, and said he was running 13.5 stock. I've seen stock SHO's run high 13s/low 14s stock at the same track. We chatted and I took a gander at his engine. I noticed there were some differences in the 2016 that I did not see in the 2015 or my 2014. It had composite cam covers instead of aluminum/magnesium, did not have the PCV vapor separator, and used some kind of solenoid for the crankcase fresh air vent tube.
My guess is that the solenoid shuts off that vent tube so the PCV doesn't suck in oil vapors, or at least restricts that tube flow a bit. I wonder how that is controlled by the ECU, probably by the amount of manifold vacuum is present?