mc01ta

Sorry if this is lengthy but I'll try to do my best to be as descriptive as possible to my problem. The car is a 2001 Trans Am M6, and when I get on it a little, probably between 3500-5000 rpm's I hear a fluttering sound from the right front dash area. The car has 32,000 miles on it, never pushed hard, daily driven. Mods are Ported TB, SLP Lid, and waiting to put on my Hooker Catback. Took car to GM and you know the answer, "its normal". To me it isn't, it isn't extremely bad but annoying. The car was checked for exhaust leaks and nothing was found. Is the A.I.R. mod worth doing for a non-header car? I want to limit my options to what i should ask my local mechanic to look for. Maybe the injectors, spark plugs? Am i on the right path. I'm considering this noise also being from my throwout bearing b/c it just went bad and I'm goign to buy a new pressure plate, clutch, flywheel, and bearing soon. The sound at times seems like the fluttering is coming from the shifter area but can the shifter/throwout bearing cause such a noise that it becomes a loud fluttering/ticking? Since i'm here i have 1 other noise i'd like to ask all you with M6 experience. If i'm in 2nd or 3rd and at a lower rpm and punch it ihear a metal type stall noise, very hard to describe. Can't hear this noise any other time unless its done in this fashion. Any clues? I hate having problems and any help is appreciated