[MikeK]

Well, that manifold looks kinda cool, but from a flow bench point of view the traffic jam at that intersection can't possibly be good. Reminds me of those 'put a 4bbl on your 2bbl manifold' adapters Warshawsky used to sell.

Progressive would be interesting. Convert the inner carb to operate like a vacuum secondary (no mechanical linkage) and make it a bit richer.

While you've got all your favorite C.I. welding stuff laid out make the intersection a larger, flow friendly plenum using a piece of 2" cast iron soil pipe. Total cost will be only $10 for the piece of soil pipe and $500 for welding supplies if you use the Castolin xuper 2240! When you're done you could put it in a well-used sheep pasture and play 'Where's Waldo' trying to find it.