I don't know if your king pins can cause this. If a spindle was bad (shaft diameters), you should be able to see that. You should be able to notice gouging or galling or heat bluing?
Anyway, UPDATE my info. The parts (picture) I have is from a 55-59 GMC manual. Maybe Chevy is different. I looked at oldcarmanual online and only found a 55.2 Chevy Truck manual. Did not show a picture with parts identified like the GMC manual. I did notice that the torque for nut, while spinning wheel, is 33 Ft LBS NOT 45-60 as on GMC. As far as parts, for an original "bearing set", there are three pieces. There is 1)inner cone, 2)the ball cage and 3)the pressed in outer cup. I think this is true for the inner and outer bearings. I think the replacement bearings (which you may have) have that inner cone and the ball cage as one piece.
The original inner bearing could be said to have four pieces which includes a "seal" pressed into hub. The inner deflector may be part of the backing plate, can't remember.
It seems like you need a B67 or B45 outer bearing and a B70 inner bearing.
Bottom line: These ball bearings are not cheap. This is the time for you to buy a tapered roller bearing kit. It is half the price of ball bearings and better!!! The kit is $120 and the old style ball bearings and seals are around $240!!!! at O'Reilly's.
Like this ....probably a mistake, should say 41-59
