Help, Mopar in distress.

Please, can any one of my mopar gear head friends help me out. I have an 86, D100 custom, slant six, 3speed w/man, over drive. the steering gear box has gone out. Every where I go, Im told its an obsolete item, it is manual steering, can any one help me out with a manufactor of the gear box. rebuilder, any one have one for sale? any help will be appreciated. thanks.:prayer: