Hi Cara,
Have you seen this?
https://knowledge.autodesk.com/support/autocad/learn-explore/caas/sfdcarticles/sfdcarticles/Changing-units-of-existing-drawing-from-inches-to-decimal-feet-in-AutoCAD.html
But 117 units to 300’ doesn’t seem correct.
I would also test by creating a shapefile and using the command in AutoCAD to bring the shapefile in. This will give you coordinate system options and preserve your dataset. The important thing to know when importing polygons is to check the polygon as closed polylines option at the bottom. You can also choose the data option to bring in attributes, to help you determine which segments you are looking at.
Hopefully, this maintains your length.
Good luck
Thanks,
Dawn