Do power steering boxes NEED the pump?

The way it has been explained to me is that an integral power box like the Saginaw and Ford torsion spring style has to have fluid pressure to assist the input side of the box from the steering wheel to keep from damaging the upper end components like the shaft, bearing and race, which are built lighter than on a manual box because of space constraints. A rack type assist like on a Fairlane or Mustang is a manual box with linkage assist. If you run it without rack assist it is just a manual steering gear. Fill it or any other manual gear full of moly grease and it will be fine.

The integral box may work without the assist, but its a crap shoot. You can fill it with grease and try it, but is it worth the risk of shearing the upper shaft or splitting a bearing or race and binding the steering? In a light car with prudent use maybe, but I'd rather just get a manual gear or rack and pinion. If you want quick steering,the manual steer Camaro guts interchange with other Saginaw boxes.