Solid strut rod bushing on stock strut rods...good idea?

The strut rod bushing must provide axial location through a non-moment connection. That is, the strut rod can't move forward or backwards, but must be able to pivot up and down freely. I suspect you won't be happy with Delrin in this application. Delrin is stiff and has low elasticity. The up and down movement of the rod as the suspension cycles will distort the holes in the bushings or possibly split them in half. Or the rod will be overstressed and distort.