I'm really struggling to install a new pair of these seats into my 5/71 240Z.  Removed the stock seat with it's sliders.  Attached the Corbeau sliders to a seat.  Just don't see a way to install the nuts that hold the rear of the slider to the stock frame.  Have installed/tightened the nuts for the front of the slider to the frame, but having only two fastening points seems sub-optimal.  

What's the install procedure, because I don't know it.

Are you not able to gain access by sliding the seat either all the way forward or all the way back?

The seat is all the way back and doesn't seem to want to slide forward at all.  An issue is that due to the cross rail at the front of the seat, I can't reach under the seat to access the rear fasteners, which connect the slider to the frame.  With the seat all the way back, there is zero room to reach under the seat from the rear.

 

Have you installed these seats before?

12 hours ago, kenward1000 said:

The seat is all the way back and doesn't seem to want to slide forward at all.  An issue is that due to the cross rail at the front of the seat, I can't reach under the seat to access the rear fasteners, which connect the slider to the frame.  With the seat all the way back, there is zero room to reach under the seat from the rear.

You need to figure out why the seat can’t be moved forward. It is possible that once it is moved forward the rear attachment points can be accessed.

 

12 hours ago, kenward1000 said:

 

Have you installed these seats before?

No, but I have removed and installed a lot of seats, in a lot of different types of vehicles. Many times it has been necessary to move the seat fully one way or the other to access the fasteners.

Did you test the movement of the seat rail on the seat before you tried to install it in the car. There are numerous reasons why it can’t slide for and aft. 

Yep, made sure the sliders worked all the way fore and aft, before attempting to install the seat plus sliders into my car.  

Happy to report that after much frustration, got the sliders to work, which allowed me to shove the seat all the way forward and tighten the rear fasteners securely.  

The crux of the problem was that the heads of the fasteners that secure the sliders to the chassis mounts were too tall, interfering with the slider mechanism, but only when the seat was installed.  Took several trips to my friends mill to thin them down from ~10mm to ~5mm, which was necessary for the sliders to function smoothly.

Thanks for all the suggestions!

I'm installing a pair of Corbeau seats myself at the moment so I'll keep the thin headed mounting bolts in mind but here is the kicker, the guy that replaced the floor pans welded the rear seat mounts on pointing in the wrong direction.  I need raccoon hands to remove the original seat and bolt in the new.

Suggest you consider using a cut-off disk to open up the closed sides of those frame mounted boxes.  Are the mounting holes the correct dimensions for the Corbeau sliders or will new holes be needed?

3 hours ago, kenward1000 said:

Suggest you consider using a cut-off disk to open up the closed sides of those frame mounted boxes.  Are the mounting holes the correct dimensions for the Corbeau sliders or will new holes be needed?

If I open up the inside walls then the mount looses it's strength, I suppose I could cut open the inside of those mounts then weld a plate on the outside to close it up,

The existing holes had to be widened.

I'm no mechanical engineer, but I think the strength comes from the ends being welded to the floor.  Here's what my seat mounts look like.