mounting bucket seats

RedFish said
No I said plates are needed but not nesessarily welded.
My responce will vary case to case.
When installing the correct seats I'll nearly demand it be done correctly.
When alternate seats are going in I refer to the captains chairs, tables, etc., in conversion vans. Splained myself I think :)

It shouldnt matter wether they are correct seats or not, mounting them safely should be a similar procedure.
Try to tie into the existing outer mounting tabs if possible. If not cut a piece 1/8" steel to cover both the existing stud hole and the new one. Bolt in place through the old hole and weld down the plate with an inch or so of bead on each edge, if possible. Also weld in a pair of steel plates (3"x4" or larger) on top of the pan in a similar manner for the inner seat studs. Of course make sure your seat is positioned to allow the door to close, not too close to the tunnel, is back/forward enough, etc. before drilling or welding. Also check seat bottom cushion height and compare to original. Too low will be uncomfortable, to high and you'll have to take your hat off or it will do it for you :-D
Belt and suspenders guys, you dont want your seat flexing and cracking the floor.