p4452893, Standard or W5 intake

Did some more research on the intake manifold.... casting number 4452893

From what I have been able to determine this manifold is an early casting M1 manifold (center thermostat location)for standard port heads and was probably sold under part number P4452891.

The later version of this manifold, with the Magnum thermostat location, was sold under the same part number but had a casting number of 4452892.

Why the this particular manifold has the W2/W5 spacing is another question but it surely appears that the manifold wasn't welded and redrilled for the wider spacing so it was probably factory drilled.

Why .... Maybe just another factory error?