PS troubles

I have 71 Duster with power steering. Box is shot and is the small sector. Parts dealers list it when you go to order it they can't get it. If I can find small sector manual box would this be a bolt on? I have ordered ps box and can get later 73 up but then all the pitman and center link need changing. Anybody got a small sector manual box and would this fix my problem? I would get rid of ps in a heart beat if I could.