YES 5.9 Magnum manifolds work in early A bodies. Here is exactly how!
Yes, that's the only way it can be done if you want mandrel bent pipe. Walker sells the flat flange on ebay. The donut can also be found on ebay. You have to weld the mandrel bent pipe to the flat flared end with the flange in place. Most muffler shop can put a flat flare on some 2 1/4" pipe.
