How were the passenger seats of the early 240z's attached to the seat mounts? Was there some from of fixed rail that the seat bolted to & that bolted to the unibody? I'm thinking of removing the sliders from my Miata seats in an effort to lower them to allow for greater comfort without cutting out the existing brackets.

Passenger seats were mounted to the body exactly like the driver side - 4 bolts pointing down from the adjustment slider, inserted thru the floorboard mounts, secured with plastic spacers, lock washers, nuts. At least that is the situation on my car.

I tried a pair of older Miata seats and I found I would lose a lot of travel on the sliders because of the steel pan on the bottom of the Miata seat would hit the front cross member. I ended up using Integra seats because they are flat bottomed.