I got an aluminum flywheel installed along with 3:73s. Just past the 500 mile break in mark and wasted no time seeing what this new upgrade is all about. WOW is all I have to say. The car revs up so much quicker and it pulls so much harder! It feels much more violent. This is the way they should have come from the factory. Highly recomend! The car just feels so much more responsive. Just passing someone on the freeway is lots of fun now. I am running a 20 inch rear wheel so from what I'm told it's an equivalent of running 3:55 with a stock rim size. Anyone with more knowledge feel free to chime in about this.