"Anyone who says HP manifolds don't leak hasn't experienced an HP manifold leaking. I had one leak. Now place yourself in the middle of nowhere without a reputable machine shop. Now bust out the hand files and emery cloth and sit there for 10hours sanding down the entire flange of a 40 yr old cast iron manifold (happened 2 years ago)".


true that. They leak and when they do it stinks. I got to the point that I used exhaust mani gaskets on a few BB-mani combo's.