[72ArizonaBurb]

I mounted a set of bucket rear seats from a Denali. I am assuming you are mounting a bench seat. I set my seat back on the upper ledge to provide more leg room for the second seat passengers. I had to drop the gas tank to run the mounting bolts in the back. For the front brackets I had 2 blocks of 4 x 4 tubular steel cut 4" tall for my outer mounts and 3" tall for the inner mounts. The floor board is not flat therefore the need to cut one 1" shorter. Here is a picture of mine. Hope this helps but it may not apply to your application. Giving this a little more thought I may have only need to drop the gas tank to mount my 3rd row set of seats.