Taken from the Haynes Manual 365 Rover 3500 V8, in the supplement part which covers the later (series 2) models:-
Page 251, section 14, sub-section 6
I quote:-
"With the luggage area unladen, and the underside of the vehicle free of heavy mud deposits

, measure and record the distance from the centre each rear wheel to the point on the wing vertically above the wheel centre. The distances should be between 15.75 and 17.75 inches (400 and 500mm); if not renew the self levelling unit(s) on the side(s) concerned."
It seems acceptable to have a varying ride height of up to two inches (or 100mm)!!
A bit vague perhaps, and the accompanying drawing appears to be a standard car, hence presumably we subtract Ramon's figure of 30mm, therefore perhaps the Vitesse height should be between 370 and 470mm? (sorry, don't know what that is in "old money") which also ties in with Chris P's Vitesse ride height figure of 373mm
Hope that helps