Hello Sheri,.. so, the obj will be used or converted (reverse engineered) and used in your design?.. or just a reference/placeholder for your design?
..if you just need to use it as a solid/surface reference,.. but the polygin/facet count is huge,.. you can reduce the facet count by using another program (meshlab, rhino3d or other mesh program) which shrinks the size down to something manageble? (<20k faces)
Otherwise, can you share it so we can look at it?... or, do you need someone to convert (reverse engineer) it for you? That is, as a project/contract?... I'd be happy to help/quote it?.