Thanks for the interest and the link guys. I'll check it out. Don't be to harsh on early responders as some of them have become interested.
After about a month of nationwide search, I have been unable to find someone willing to part with their stock plastic manifold. I have had eyes on one and PMs on a second. This will probably improve in the future. For this reason I have decided to start clean and build a simple manifold from ABS plastic. This is probably a little unusual. The standard ABS glue at a hardware store does a very good job of gluing pipe into a tight fitting hole. It should be as good as the friction welded material that we have stock. I have selected 1.5 inch ID by 1/4 inch wall thickness pipe. This will allow me some extra material to match the port in the head on one side of the pipe and match the throttle body round tube on the the other. I will loose my inner tumble butterflies but will incorporate their function into my secondary throttle plates. These are my thoughts on the secondary throttles at the moment, closed at idle (there is a gap all round). 1/4 open at 1200 RPM using the tumble butterfly control. Full Open at 3000 RPM using the runner length butterfly control.
I have selected a thick flange material because plastic flows a little away from pressure. This will keep my homade and sealed gasket snug.
MacMaster-Carr
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