exhaust to intake manifold pipe - plumbing method request

[Karl Wolf]

Intake side of the block, center, are two holes, one each side. These come from the exhaust of the cylinders 2, 3 and the 6, 7 exhaust... So, no piping from ex pipes.
There are two corresponding passages in the intake manifold to a small chamber under the carburetor... No exhaust gets to the engine combustion.

Karl