I would suggest you just have a little re-think as i would do the following:
- Create a family in revit that is parametrically setup to fulfil what the items you need to generate in revit.
- You then extract the relevant data from civil 3d and structure it in json
- then you do a read script from json to place the families and adjust the types accordingly
Doing the above will help you and also mean the items created in revit are easier to manage, if you use the directshape method it can be a pain in some instances.
Have a read of a post i did a while ago plus watch the video - JsonData Package - #31 by Brendan_Cassidy