stock or hv oil pump

The author was working for "Chrysler performance parts development" and did state that Chrysler engineers ran tests that showed the flow did not improve with a hv pump and standard size pickup.
He referenced special bottom plates with larger fitting and pickup. No source was referenced.
He did say Milondon made a bottom plate with a fitting (size?) and described using it to make a dual pickup. The Chrysler engineers used a flexible hose on the lower pickup.
I don't know if any of those bottom plates are available. Might need to be fabricated?