Need a little help to convert a .stp file

 From:  PaQ
9036.1 
Hello guys,

I'm trying to import this one from GrabCAD : https://grabcad.com/library/scania-dc09-diesel-engine-1
Here's a direct link : https://drive.google.com/open?id=1apKyseFcTDgyN9qsySA4Dg7WaZyznJSh

I have lot's of surface mess with MoI (V3/V4 gives the same result).
I wondering if anyone have access to a more advanced CAD tool that might give a better result ?

(I'm not blaming MoI .stp import, I'm just trying to find a solution to avoid too much clean-up ;))