We (well, Eric) made a set for my car, a 71. I wanted the seats as low as possible, so he laid them flat on the floor for as much as he could. I cannot remember if it was the front or the back (he can probably tell you), but we did use about a 1" round stock and drilled a hole through it to provide the support for that end so that the rest could lay flat.
The Wedge brackets will locate the seat at least an inch to inch and a half above the floor. If you are tall, this may be a problem. I had them in my first second gen, and always thought the seat (a Sparco) was too high.
Ah, I found a picture.
The countersunk holes are where the sliders were attached, and the other holes are to mount to the original floor attachment points.
Hope that helps, again I realize it's for an earlier car, but you can probably do something like this over the later humps.