Manual steering gear swap.

I have power steering on my 67 dart right now that I took off a 72 318 car. I want the steering to be a little more firm and I’m thinking about putting a manual box in it. What box would I need and where do I get one? Or is there anything I can do to make my power steering more firm? Also thinking about putting my cheap summit headers on and I’m assuming a manual box would give me more room? Thanks guys
up the caster in the front end. it will increase steering effort AND improve high speed stability.