RE: str4 pro campatible with sb sport?
Yes, you are right in thinking they are plastic but the sb v2 outdrives will not work in the sb sport or sb pro. They are not long enough and they are meant to use a new diff gear that the v2 and str-4 II use. The dogbones/cvd's on the sb sport won't reach. Did that answer your question? Let me know if thats not what you were looking for.