How much movement is allowable in the front spindles? My wheels don't seem to wobble, but I notice about 1/16" wobble in the spindles when I lift them by hand.
Not sure where you're saying the 1/16" exists. Do you mean the spindle will slide up & down along the kingpin 1/16"? Or, do you mean the spindle will move 1/16" side-to-side, meaning 1/16" clearance in your spindle bushing? The up & down thing is not that important, but the other would suggest something is absolutely shot.
You have 3 things which could be loose. Up and down as noted above, sideways in spindle bolt as noted above, and loose wheel bearings. When you jack up the car, put one hand at the bottom of the wheel and the other at the top. Try to push the top to the left as you pull the bottom to the right, then reverse the direction. Look carefully to see if the spindle moves at the spindle bolt through the axle. If that is loose, you will have less control of the steering and could develop a shimmy. Notice also whether the hub moves back and forth on the spindle when doing the test above. The wheel bearings should have smooth races, and be greased with wheel bearing grease. You should tighten them while spinning the wheel. When you begin to feel a slight drag, loosen just a few degrees till it moves freely but does not rock back and forth on the spindle. Then place the tabbed washer and outer nut. It might tighten up slightly when you tighten the outer nut. If so, back off a few degrees, tighten the outer nut and place the cotter pin. After you drive the car a block or so, check again. As the grease settles, sometimes the bearing will loosen up a bit. If so, repeat the tightening process again and it should be fine until next time you pack the bearings. If the spindle bolts are loose, you will need to replace the bushings and maybe the bolts depending on wear.
It has no up/down movement on the king pin, but the threaded end of the spindle moves about 1/16" when I lift it.
Up & down movement at the outer end of the spindle could mean worn spindle bolts and/or bushings. It could also mean the threaded hole at the bottom of the axle is "wallered out".
Yes, that's similar to mine, Mike, though maybe a bit looser. Are new spindle bolts generally installed along with the bushings?