Just musing.
I am a Roots fan but Ya know..... that's some serious weight to hang out on an inline 6 manifold. It's going to take some serious support work. It's also going to take some long strange snout and pulley work to line things up. I am kind of wondering if one of the centrifigal chargers would be a better choice overall.
One more muse if using the Roots.
Instead of sitting it upright in the normal hot rod manner, hang it vertical like it was on the Detroit diesel engine it originally came off of. Manifold construction and alignment should be a more straight forward undertaking.
Dave Koehler
http://www.koehlerinjection.com