Unfortunately you cannot do this in AutoCAD Plant 3D 2010, but we are hoping to fix this for a future release.
Currently all that can be modified, added or changed is items that currently exist in the availble catalogs.
The ASME and DIN catalog objects can be copied and dimensionaly modified as well as descriptive and connection information.
The AME catalogs are block based objects the were converted from AutoCAD MEP content. These objects cannot be dimensionaly modified. The discriptive and connection data can be modified.
Mike G (autodesk)
Michael Gulnac
Technical Specialist
Organization
Autodesk, Inc.