What I found was -- An essential copy of the cast-iron manifold, the runners were raised about .125 inch to match the cylinder head intake ports and improve airflow. ....so there is some gain.
What I was after is more isolation from the exhaust heat due to ethanol lowering the evap temp of gas. Also I would never think of putting a fuel injection kit with the computer in the throttle body due to Pontiacs hi heat at the intake, computer chips pop at @125-140F.
