Maybe, just maybe, the scoop does provide a ram effect( you are over 150, after all !) that the filter and elements cancel out. The filters cost next to nothing on the dyno, yet you picked up(apparently) a bunch of power without them at the track. It has to have something to do with 150 mph airflow that is different from dyno airflow.
i looked at the incrementals and from the 60 ft clock forward there was gains like you would expect from ram air virsus disturbed, turbulant air. Very small gain 60 to 330, 330 to 660 more gain, over double from 660 to 1320.