We get contacted pretty often by people that have cracks in their Mopar stage 3 turbo/manifold on their 2003/2004/2005 Dodge SRT4.
These customers will ask us if we have new manifolds for sale. These turbo’s and manifolds were discontinued years ago, and are no longer available at all, let alone new manifolds.
So, the best thing to do is find a good welder that works with cast iron. Then, the welder will grind the crack, and use a special welding rod to weld the crack shut. Thats the best, and only option to repair a crack in your stage 3 turbo manifold.