No. CAD files created using AECC_Contours are not supported by ESRI software. AECC_Contours are Proxy Entities from AecCivilBase, an AutocCAD add-on.
If this data can still be seen within ArcGIS 8.3, it is recommended that it be converted over to an ESRI supported format, such as a shapefile or personal geodatabase. The file can then can be brought into ArcGIS 9.0. It may also be possible to use the Export utilities in AutoCAD to convert the feature geometry to standard polylines, which are supported in ArcGIS.