We see this quite a bit. Make sure to dress the leading edge of the shaft where the fast idle parts go on, as there is often a "lip" there that makes the shaft push hard thru the new bushings.
If the shaft turns hard in the bushings, it's tweaked slightly and not perfectly straight. I often have to fiddle around with them a bit, like a Buick that I was working on yesterday. The shaft just turned too hard in the bushings for my liking. A long straight drill blank verified the bushings were fine and in good alignment. I was able to get the shaft to turn freely after some minor bending in a couple of places.
Use extreme care when doing this, as the shafts are easily broken!....Cliff