I believe that's what Krazy is saying. No need to swap the steering box, just the pitman arm and other manual linkage if you got it. - Matt
Yes ... grab the pitman arm off the manual box, which will probably require a gear puller, and swap all the linkage from the manual car.
Yep keep the power sector but replace pitman arm, center link and idler arm with manual steer parts... I think you can use either the P/S or manual tie rods as they should be same, also probably the idler arm but were different some years...