5.2 Magnum exhaust manifolds on a Valiant?

Heer is an article on how to install them on an early A. He uses the Durango/Dakota manifolds, so I don't know if they put the flange further back than a ram exhaust manifold or not. These would be chaeper than TTI Headers by far, I think these could be had even cheaper than the spitfire headers. I think performance wise these would be the worse of the other 2 mentioned above.
http://www.geocities.com/lars_an_artist/durango.html