Bench to Buckets...need help!!!

You should find 4 dimples in the floor on each side. The dimple/hole spacing is a little different on each side of the car. If your brackets are truly specific to the car, each one will be a little different. The outer dimples are near the bench seat risers. If you drill through those they'll already be reinforced underneath. The inner ones (near the trans tunnel) are not reinforced and you should do something to reinforce them. The floor is not flat so unless they made the brackets in a way to compensate for that you may need to add spacers.

I did an aftermarket seat install recently and have pictures on my site that might make things clearer for you. www.70duster440.com Go to my "Repairs/Mods" page.