Rear track and front track shocks on ALL 800/850 AXYS ProRMK's are the same length as other AXYS sleds (2016/17/18)
The IFS shocks (ski shocks) are a little shorter on the new front suspension on ALL 2019 ProRMK's (800's and 850's).
They did not say how much shorter though.
The measurement will soon be available... and I'd bet that your current shocks can be shimmed to take up the difference... we've been doing that with the narrow front suspensions for years on the ProRide and AXYS mountain sleds for years.
Almost an inch