The "theturboforums.com" has forum for intake manifolds. Its moderator is a former ford engineer that designed the intake for the '80s 5.0 and has tested other manufacturers systems. A very good read. The "victory library" ran by "panic" also has a good section on intake manifolds, geared mostly towards carburetors. Don Dolmtech, mostly noted for big blocks, has a series of articles on his "senior dragster" on "the hamb", they include a couple of intake manifold builds.

Both Don's and " panic" theory's on the 225 were not well received here.