bucket seat mounting location.

The buckets do sit lower than the bench. For shorter owners, the dealers used to install wood shims under the tracks.

I drove for years with big washers. The reinforcement plates weren't available at the time. Since they go on top of the floor, they are supposed to be welded in. They won't fit underneath the floor, if you are thinking of that -- one of the holes is very near a brake line, and there are other obstacles.