I'm not sure about this and would like to know

Will gear effect MPH? I can see it effecting ET by 60 ft'ing better but HP calcs don't ask for gear. they just ask for HP and weight and since this car in question doesn't MPH either I have to question whether gear is the obvious reason. If anything, a really effed up converter might be the problem

like Cab said, maybe the filter is the problem but at 9 lbs crossing the line, Could that really be the problem? Now, if 9lbs is to much and your flooding the engine, I would think if your dumping way to much fuel in the motor it could be washing the plugs clean but they would probably be dripping but would cause the engine to be way down on power.

taking it to a chassis dyno is something I would do. maybe your timing light is off from the one used on the dyno. are the secondaries opening? when you figure this out, i'm sure we would all love to hear the results