everyone above is right on the money...

Diamond-Elkins used to perform a maxi-interconnect where the center of the intake was cut out and raised for more plenum volume.

This mod is outlined in the old direct connection manuals. If your curious let me know I have one somewhere I can scan.

It helped.. didn't look remotely stock.

On a modern race motor or stroker it will be the restriction.

For a street car ..awesome