The vertical CG position is going to depend on the fuel quantity and the number of passengers and other variables. With little or no fuel, the CG will be higher than with full fuel and passengers.
As far as I know, no-one ever bothers with determining this position, which is a shame, as it has a huge effect on some lateral directional handling. See my book- The Art and Science of Flying Helicopters, for details of how it affects this.
Shawn

Check Prouty who has some interseting points - the theoretical height of the mast for the OH 58 is infinite for stability problems of that particular type of underslung hub - material limitations restrict the mast height to around 50"