[Bigdav160]

The PS truck boxes are similar from '68 until '87 or '91 for Blazer/Suburban.

You '67 from probably doesn't have the dimple in the frame to clear the box and most people use a spacer. This causes your pitman/idler arms not to be parallel with the frame members but unlikely to be a serious issue.

I do not know if your current steering linkage can be used. Many gain power steering and disc brakes when they convert the whole thing over from a later model truck.