That kind of design is good for N/a or FI systems, the "do or die" factor in the design is the plenum. This design is great for the forced induction and doesn't need a higher flow space design like you would with N/a builds. Read up on tuned intake manifolds/runners, and even intake reversion...its an old, but still tested and proven way to design these things.
I have been tinkering around with my own manifold off and on, but haven't got much further than design and aquiring material. All you need is a plate to be cut out (water jet or laser places) to match the surface the orginal plenum bolts to. You can either bolt the plate on and then weld the plenum to that for sold one piece design, or if you have a great welder that can weld cast materials you could weld the new plenum straight to that.