I currently have a 2001 GT, Vortech v2 with intercooler, Kooks lt headers with catted x pipe and magnaflow catbacks. I'm making 380 rwhp. My tuner suggested going with lower gears to "wake up the car" and make up for some of the torque I lost when installing the headers and intercooler. I dropped about 2 lbs of boost and am now at 8.5 lbs. It is only in the higher rpm's that I feel my car really take off now. I currently have stock rear end, 3.27 gears. I am thinking of moving up to 3.73. Right now I am running Michelin Pilot Sport A/S 3+ 285/40zr18's on the rear. I get great traction and never worry about excessive spinning when flooring it. Will 3.73 gears create excessive loss of traction, and will I still have any functionality in first and second gears?
Probably cheaper to drop one pulley size and see if that is the pep you were looking for.
Stock block can take a pulley size drop.
If that is not enough pep than look at your long term goals and determine what gear lines up best with the 1/4 mile trap speed you are looking for at the top of 4th.
3.73’s are the most I would go for your power level with a stock tire height.... you will be right on the edge of running out of gear. Personally I still have the stock gears because I spend the vast majority of my time on the street and I am planning for more power.