The only way I could find was to modify the door objects, to provide the dimensions in the format I wanted.
Our office is using the SmartParts collection of doors almost exclusively.
I did some custom GDL magic on them to make doors read 3'-0" x 6'-8" x 1 3/4", and to list double doors as (2) 3'-0" instead of 6'-0".
I had to modify each object. Since the SP kit only has about 8 or 10 doors, it was not so bad The GS library could really take some time to modify, and is much more subject to being updated, causing you to have to redo all the work.
Tom Waltz