Seat Track Packing Spacers
There are wood packing strips between the seat tracks and the floor. The wood strips have holes of approximately ¾” diameter that the mounting bolts pass through. I suppose that the holes are this large to allow for lots of adjustment-to make starting the bolts in easier.
Large metal spacers go in these holes. The spacers are important. If they are missing, the wood packing strips will get crushed and broken as the seat mounting bolts are tightened.
Two spacers are need per seat track-or four per seat.
Spacers are Aluminum and they are often badly corroded-often so much so that they break into pieces when the bolts are removed!