Ah, why I dislike aftermarket... The AussiSpeed Dutra Duals are much better than the raw castings that Doug put out but they are not perfect... Lots of grinding and touching up on the Dual and the Offy manifold to get both to be free floating and not touching each other or the studs. This is a _requirement_ for /6 builds, those parts float and move around during thermal cycling. Need to be creative to get the batwings and nuts on the lower side of the manifolds.... wires, screwdrivers and a steady hand required.