I know exactly what you are talking about. I have been on a similar search for the last 2 years and the closest thing I could find was a old 4x2 manifold for the old poly small block. Also been looking for an old Hillborn style injection system for a smallblock. The ones I do find are expensive for worn out junk and only 1/2 there. So my solution was to have a guy cut me some manifold flanges on a CNC machine - out of 1/2" steel plate then plane them flat. I don't mind the hassle of welding up the runners and a plenium (if I go that way). But they want a fortune for Stromberg 97's or equivilent. D'lortos and Webers are too much $$$. So now I am looking to modify an old mechanical CIS injection sytem (port) to look like a Hillborn. The idea someone mentioned about cutting an aluminum manifold is food for thought. If you find something of interest let me know and I will do the same