This big port manifold was intended for use with the 57 and up big port heads. It is probably the best flowing dual plane multiple carburetor manifold. Note how both carburetors are centered over the runners. The unique design of the passages in Y Block dual quad manifolds allows the primaries of 4v carbs to supply both manifold planes whether the carburetors are mounted parallel or perpendicular to the Y Block centerline.
This manifold is in very good shape. There is no corrosion and the ears and threads are in very good shape. (Note: no cross threaded plugs that are difficult or near impossible to fix)
Price $400.00 plus shipping
Sold on Ebay