i have a 97 cobra stock should hit 13.9. what would i need to get to low 13s. im thinking of getting headers h pipe and some 3.73 gears.

 

you can hit low 14's high 13's pretty regularly with good launches. Gears (probably 4.10) and DR's should honestly put you in the mid-low 13's on a good run. Midpipe, Headers, catbacks, and a K&N/CAI with gears and Dr's will put you in low 13's no prob.



EDIT: The place I had dyno my car gave me a little advice on exhaust and showed me a few graphs of the 97/98 cobra's he has dynoed and he showed between 5-8hp difference in cars with nearly the same mods, main difference between them being the H pipe or X pipe. Cars with the x pipe were putting up slightly more hp... take that for what you will, but that kinda changed my mind. I was looking at an H pipe as well for the sound.