Hello All, I have a 1963 New Yorker with a 413 4bbl engine in it. It has single exhaust right now, and I'd like to convert it to dual exhaust (with a cross-over (H) pipe)). I know the 300 model this year had dual exhaust and even dual quads. I would like to upgrade to that exhaust. Does anyone know if that car also had different exhaust manifolds as well? Is there anyone out there that remanufactures factory exhaust for these cars? I attached pics of my exhaust manifolds below. As you'll see, they aren't necessarily performance manifolds. My passenger's side manifold has PN 22055JS on it (last 2 are a guess). My driver's side manifold has PN 22055S8 on it (last 2 are a bit of a guess).