Actually, that would be bolts.
My 64 started pulling slightly to the right 2 days ago. I also noticed a slight "clunk" upon heavy braking. When I raised the hood, voila - one of the poly inserts from the bushings in the upper a-frame was GONE! The metal sleeve is still there, just the poly piece is gone.
Apparently the bolt had backed out allowing the poly insert to squirt out. All 3 other bolts were tight.
I pressed the rubber out of an old stock bushing and installed it with the help of a crowbar to center the a-frame, and longer bolt to draw the rubber into place.
those with poly bushings may want to check their bolts.
Now to order and install a replacement poly..

next time put some grease between the washer and the poly insert, the motion of the car going up and down in turn creates a twisting force on the poly and washer, turning the bolt and backing it out all by itself.