Conversion to manual steering

On my 71 Scamp I'm going from power to manual steering. With the power it floats everywhere, its just way too light. It has a 360 with HP manifolds, if I pull the manifold I think I'll have the clearance to lift the old box out. Am I better with 16:1 than 24:1? I am looking at the PST boxes. Besides that I just need the steering column adaptor right? Mancini Racing Manual Steering Adapter Does the pitman arm need to be replaced?

Maybe you need more positive caster. Have you had it aligned lately?