<VV> Rear seat bolts

[Scott Candish]

I'm installing the new interior in my '65 & do not have a Fisher body manual. Neither the GM assembly manual or the Chevy Corvair shop manual for the '65 shows seat attachment diagrams. Are the 6 1/4x20x1" bolts w/ captured washers that held the old seat screwed directly into the pan,into bosses welded to the pan or are there nuts on the other side? Mine will screw in but pop out.TIA.
   
  Scott
  65 Corsa
  UNSAYF