There should be an option under "Feature Notes" that allows you to bring in the welld dimension values created in the model. At the very least allow the dimensions to be imported through the import dimensions command.
Please see the following link that speaks to this.
http://forums.autodesk.com/t5/Autodesk-Inventor/Retrieve-weld-dimensions-on-idw/m-p/4476175#M484200