So I did this mod today, didn't use a metal plate but picked up one made out of mr gasket header gasket material, it came with 9/32 and 11/32 holes and immediately when we started the car up I could tell a difference, rpms come down much faster and the car kind of sounds like it has a mile cam now @ idol. Was not able to test drive the car but maybe tomorrow early before the N.Y.E. crazies hit the roads.
Thanks for this awesome info