I have the sector support on my car but I didn't really notice a marked improvement? It doesn't hurt to have one though.
Have you reinforced the box mount on the K frame?
Also, I'm sure we've all noticed the box, linkage movement when watching with the car running and someone turning the wheel. I noticed less dramatic movement with new idler inards. It seems like the FF roller brg wall but eliminate that bit of slop.
Pretty pricy on both parts, so some real world experience is helpful in decision making.
