I've a '90 Ram 50 2.4L (a 4G64 I think). If I understand correctly, there are two arrangements for the -- I don't know what they're really called -- the "ports" from the block running into the exhaust manifold: they can be evenly spaced [ 0 0 0 0 ], or in two offset blocks of two [ 00 00 ]. Does that tell you anything about the engine code (e.g., 4G64 v. G64B)??