Pic of half manifold complete from the coupe.

Pic of beginning half of manifold from the 1000 wags.

Modified forklift manifold from my old 1200 sedan.

J-Pipe setup I made for a 1200 sedan and the years later modified for 120y wags.

L18_B110 and I have had lengthy discussions about manifolds and one thing both of us can agree on, is that J-Pipes are a good simple design that function well.
When it comes to full manifolds you have to think about the motors intended purpose, street or drag. There is lots to research on design. Short log style manifolds might be good to for speed delivery, but they supply lots of heat to the turbo. This heat will soak into the compressor housing and increase inlet temps. Drag motors that run for 15 seconds wont be affected by this. Street motors are a different story. I believe the Gibson Exa might be a good example of a motor thats designed to run allday without fail.
Has it been researched what the costs are to make moulds and having manifolds cast?