When the Edelbrocks were stock and unported, we used a Mopar M1 manifold. We then had the heads ported by Brian @ IMM and at the same time I switched to the Super Victor. THe car went from 11.20s to 10.60s. I wish I would have done the manifold swap after running the ported heads. So basically I cant even give an honest conclusion as the affects of the manifold vs. another one. We have a 2" tapered spacer ontop as well and the manifold is TALL.