Individual runner as opposed to plenum type.

I found the manifold in a 1974 catalog; I have no clue as to if it is still available. Generally, everything for which I think I need is no longer available, and I have to find used versions.

Jerry - not arguing for more air, just "better" air wink

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop