how much room in the cab for us bigger people

[master 1969 c10]

hi am currently building 69 c10 fleet side from the ground up. I am a big guy 5'9" 400lbs i have a tilt wheel and plan on push the steering column as close to dash as i can and putting a smaller steering wheel on will i fit. I want to here from my bigger buddy on here or any other ideas u have or done that help. yes I no loose some weight but when your disable it's hard. I would like to here from my king size buddy's Thanks Doug