What parts do I need for steering?

Search on this site for user 67dart273, he has a thread with all of the factory manuals free for download in PDF form. I also bought a book on Amazon just to have out in the garage with me. Do you have a K-frame? That'll decide which year parts you need, IIRC there were some differences in years that don't play together. Parts off the top of my head; idler arm, pitman arm, center link, two inner tie rods, two tie rod adjusters, two outer tie rods, steering box(power or manual), and a whole column. A lot of these parts you can pick up here on this sight for pretty good prices. If you're going to go power you'll want a column from a power car, manual with manual car. Being a 73 you'll also want a column with ignition in it. If I were you I'd try and find someone parting a 73+ car and grab all the big items, ie. column, box, center link. The rest of the parts can be found on rock auto et al.

Have fun!