Take this from some one who drag races, its not going to make any difference unless you are drag racing on the track or running WOT ALL the time. That's the only time having the 90mm is going to give you an advantage over the stock one, during partial throttle operations which is ALL the time your driving on the street its going to open the same amount to allow the limited amount of air the engine needs to run. And to add to that if you do install it you will need a tune to take advantage of the more air coming in at WOT.
So my advice is...Unless your drag racing or running WOT ALL the time it does nothing for you. If you are wanting crisper throttle response; a cheaper and more reliable mod is Pedal Commander.
Thank you Kenny, I do have that peddle commander and love it. I plan on racing at our local drag strip once in a while and next year will be long tube headers and cat back system. I haven't put on that 90mm yet.