Go to this site at the bottom of this note. You will find in the second row of prints down a top and side view of the seats with the important dimensions.
I found a local guy to bend and weld up the tubing and a sheet metal shop to make the backs. I am using vinyl over marine foam rubber for the seats.
FYI the left front and center seat are the same dimensions so all you need to do is change the way they mount to the floor.
I am keeping the third seat simple, 46 inches wide.
As old and scarce as these vehicles are there is no one alive who remembers them any way so how can they criticize them.
They mount to the floor with key hole type slots and toggle bolts with wing nuts.
www.46chevytruck.com/46suburbanrestoration.htm