Which exhaust manifold works? Went from 318 to 360. 1970 Duster

Last weekend I dropped the new rebuilt 360 in the 70 duster. And thanks for info on motor mount differences I found in forums. The car has power steering and the manifolds I got with the 360 hit power steering box. Trying to stay away from headers. I read somewhere 340 manifolds will work. Anyone know if fact or fiction? What year? Etc.? Any help would be appreciated.