Hey Kevin,
I took a look at mine, which is a 3/4 ton, and the steering box is mounted to the inside of the C channel with two bolts coming through the top of the frame to the steering box. Maybe someone with a big bolt will help with more info.
Good luck!

~ Victor
1941 3/4-Ton Pickup (in process). Read about it in the DITY Gallery
1955 Grumman Kurbside "Doughboy" 235/3 on tree w/ OD
1957 3100 - moved on
1959 C4500 Short Bus "Magic Bus" - moved on
1959 G3800 1 Ton Dually "Chief" - moved on
1958 C4400 Viking "Thor" ~ moved on to fellow Bolter