well i have my shift light but my pills only go up to 5.8 which was on the old gt.... whish rpm is it best to shift at on my 97 cobra?? look at my mods in the sig. if it makes a difference... should i buy the 5.6k rpm -6.4k rpm or the 6.6k rpm to 7.2 rpm?? i dont know where these cars should be shifted at for best performance... anyone with more experience wanna give me an idea??