Hello John,
Check the chart on page two of the attached snipit from the documentation on GEOPAK drainage file import/export. It shows the mapping for library objects between GEOPAK/PowerCivil and StormCAD. You should be able to use Grate, curb, slot and combination inlet types. What type of inlets are you using in the StormCAD model? Feel free to share your model with us using either method below:
1) If you are OK with sharing your model with the community: click the "attachments/Options" tab in the advanced reply editor and attached a zip copy of the model (.stc and .stc.mdb for StormCAD 08.11.02.75 and below and .stsw and .stsw.mdb for 08.11.03.77)
2) If you'd prefer to keep the model confidential: submit the zipped model to our secure upload location. Bentley colleagues can access this.