REST Service does not project from WGS84 to GDA94

[RobertWagner1]

Does anyone have an idea why the Geography service gives the same result when I project from WGS84 to GDA94. I'm expecting a slight difference.

Eg for the point 152.491344, -27.547577, the exact same value (152.491344, -27.547577)  is returned instead of the expected 152.4913395,-27.5475863

ArcGIS/rest/services/Geometry/GeometryServer/project?inSR=4283&outSR=4326&geometries=152.491344%2C+-27.547577&f=pjson

{
  "geometryType" : "esriGeometryPoint",
 
  "geometries" :
  [
    {
      "x" : 152.491344,
      "y" : -27.547577
    }
  ]
}

[nicogis]

they have different spheroid so I think that you need pass rest also Datum Transformation (available from 10.1): http://resources.arcgis.com/en/help/rest/apiref/project.html