I am going to attempt to install 66 buckets in my 67 Barracuda. But I need to remove the floor pan bolts from the seat tracks so I can better check how they sit on the floor pan.

After removing some of the rust, it looks like they are the square carriage type bolts and should be removable. I tried to pound out one with a piece of wood, but all that did was put a hole in the wood. Before I get too rough with these, I need to know, are they removable?

How much different are these from the 67 seat tracks?

I don't remember the details on your tracks; I seem to remember that they're like the later ones, but I'm not sure.

On the later ones, the bolts (studs) are part of the track and are not meant to come off of it. Those studs are made of very hard steel, and a nut with attached washer on the underside of the floorpan holds the tracks to the floor.

Often, due to rust and age, those nuts are very hard to remove the first time - you may have to use an impact wrench. The next time goes much easier.