I remember when I was running 225's, there were two different size outlet manifolds. We found the larger outlet exhaust manifold, and that along with the super six and cutting the head .100 really was like adding another engine to it.
I've looked and looked for a manifold with the bigger outlet. I have either six or seven now. all of them are 2" or less. I would love to find a big out manifold before I put this back together. I don't see it happenin.