MANIFOLDS: The passenger's side Magnum manifold will fit a '67-'76 A body, but the driver's won't fit w/power steering, as the box is too bulky, even tried a Jeep Magnum manifold and no dice without a LOT of grinding.
I have a '74 Duster and it looks like it may fit with the current spool k-frame and low mounted p/s pump. The steering column shifter linkage looks dicey though.