Need dual exhaust for my /6

sorry I forgot about the other Q. the slant six manifolds are all the same from beginning to end they all do not look the same and their are many casting #'s but they all pritty much have the same flow. the only exeption to the rule is in the early 60's they had a hyperpack manifold set up that was a long ram 4 bbl intake and a split duel manifold the dutra is the closest match to the original hyperpack performance and layout