Isn't only half the manifold wastegated? I was under the impression the SPA manifold is a twin scroll manifold where only 3 cylinders are directly on the wastegate?
If you were interested, I got a quote for a pair of SCE ICS Titan copper gaskets. They will only make them in batches of 2 or more. It is ~.041 compressed with integrated O-ring and a 3.950 bore.
