71 Dart Steering Box Leaking

So my power steering box has been leaking for a while and I've tried using Lucas Power Steering stop leak but it only slowed the leak. I'm assuming my seals in it are done. I've never taking the steering box off or worked on one. Is this something that I should just bite the bullet and replace the steering box or would there be some easy o rings or seals I could try to replace before doing that? It has power steering and a 318 with Hooker headers if that helps.