I have a split bench front seat I am installing on a 1971 Cutlass Supreme. I took it out a few years ago and now after restoration am putting it back in but trying to figure out how to bolt the back down. There are two 'offset' bolts in the floor and two holes in the rear mount of the seat that are NOT 'offset'. Does the seat just get set into one of the rear bolts and secured? What is the other bolt for? see pics for better description.

 

Yes, just use the two bolts that line up. Although I don't know why the bracket has three holes yet only uses two.