In my opinion, strut rod bushings should be rubber or heim joints. The way the strut rod/K-frame interface is constructed, the bushing must compress and de-compress with each up/down movement of the suspension. Poly is not compressible enough for this task.
When using 6061 T6 aluminum strut rods, I observed flexing of the strut rod when used with poly bushings, but not with rubber bushings.
I reccommend that you cancel the order for poly, and get rubber.