"T" bone. I say that because when I bought my 58 stepside I was driving it home and stopped at a gas station the 1st time and I guy pulled up next to me and said Nice truck.. did you relocate the gas tank? Then told me this story of a friend would succumbed in a wreck because of the location of the tank. Needless to say I took that as a sign and relocated the tank to frame. They make a plug for the filler hole. I have that but not welded in yet. I rigged up a Harley Davidson cap from the inside to tighten up and seal. A small block of wood on the inside with a nut. I see no advantage to having the tank behind the seat.
~ BD. "You won't find me in an old folks home" Pioneer Florida Cracker 1958 Apache Stepside 1958 Apache 1/2 ton Panel 1959 Apache 1/2 ton Panel