You shouldn't have any problems widthwise on those 235/85R16's. They might be too tall for the opening, but they're not too wide.
I'm running a '46 3/4 ton with 235/75R15's on it. My truck has got the same axles and brakes as what you've got, and they work well for me.
I gotta agree with bill on the power steering thing, too. Much easier to maneuver.
