bucket seat hole location

Sorry you feel your help and information is unappreciated. I appreciate it and wish I'd had it at my fingertips at the time I made my reinforcements. However, rather than insults why don't you enlighten us as to why 1/8" plate welded to the underside is so inferior?

My reply was to snake. I'd didn't intend to insult anyone.
This has been argued before by others. Folks get the idea that the plates are meant to prevent the seat attaching nuts pulling through the floorpan in an accident and when placed uder the car they still do that. Their main purpose is to reinforce the floor pan due to the repeated stress from the sitter (you).
I could try to type out a long explanation and still someone would argue.
It's much simpler to suggest you find a rocking chair to sit in. Your feet on the floor will replicate leg movement of driving. Add to that the push and pull of your arms. Now imagine the rocking chair bolted to sheet metal.
That should help you grasp the concept.
One more thing is what if there aren't any inboard reinforcement plates installed ?
Over time the floor pan will distort. Eventually the tracks will be so far off plane that they bind when adjusting forward and back. Cheers