At least that since I would have fabricated one myself a long time ago if I really wanted one. I was just curious.

Hardwood and a router. Been done several times back in the 70’s.

And the calibration process on the Weiand was done in Michigan, and that was a scary process that an engineer came up with.

Might look into that but no domestic types, maybe gum but I’m thinking imported with a very dense grain (heavy & $$). I’ll check my supplier next time I need some materials.
Also the Carters carbs line up nicely sitting on the front and back bolts of the two barrels (outermost bolts)

I seem to recall 7 ply baltic birch plywood. 20 years ago when I was thinking about making a top for 2 sideways Holley's I was going to make a spacer out of wood or nylon with an aluminum top. Then I realized I would probably need thermocouples and O2s in all 8 cylinders to figure out the extreme stagger that manifold needs. That is why a new, unused manifold and both tops are still in a rubbermaid bin.