Jonald,
Excellent description and observations. This is a common problem. Someone posted (a while ago) a part number for a king pin set with over-sized outer-diameter bushings. As you note: these would need to have the spindle/knuckle's bushing hole/seats/socket bored/reamed out to fit the outer diameter of the bushings.
Regarding used spindles/knuckles: most used ones that I have seen/bought are "wallowed out" and not useable. Be careful buying a spindle/knuckle without first testing the snugness of the floating bushing.
showkey,
"Most of the over size kits use larger outer diameter bushing and the same size pins."
What is a brand and part number for one of those kits? This information would be quite helpful to many people. I have only seen over-size kits with over-size (.010" & .020") king-pin diameter (to fit in a reamed-to-match hole in the axle).
