Power steering for my 1966 plymouth Valiant 273 V8

BAC STEERING BOX UPGRADE MASTER KIT - Bergman Auto Craft
obviously you'll need to call and talk with peter and suss out the details, but he knows what's up and and put together a complete slam dunk kit.

or: you source a stock steering box, power steering pump and brackets, corresponding pulleys, hoses (stock or custom), belts, then you'll need the correct pitman arm to match your centerlink, and a manual to power steering coupler (or power column).