69 Dart 360 exhaust

Hi, I have a 69 dart with a 360 and power steering. Currently I have the 273/318 2780945 exhaust manifolds on it. Are the expensive 2863549/2863553 340 manifolds my only option? I do not want headers. Will those 68-70 340 headers work with power steering? Sorry, I know there are a few threads on here regarding this but was still kind of confused. I guess the second question, am I wasting time/money by changing manifolds? As far as I can tell its a fairly stock motor. Thank you