It seems from what I gathered that the stock power steering box would be okay. It'll be tight but from what other people said it should fit. You'll have the same issue with the steering column ('67 specific issue) getting very close to the #7 header tube, so you might have to clearance that.
One thing that might be an issue is that the steering centerlink/idler arm also is one year specific for '67 but summit does list that the headers fit on a 67 barracuda so you'll probably be fine. A mini starter is definitely a must if you have an automatic. Hope that helps. Oh, and you might want to pick up some new engine mounts before you start the install to make sure you minimize any fitment issues LOL. Good luck, let us know how it went.