^^^Depends on how skilled you are as a driver.

 

it depends on your boost with low boost like 6 psi and a smaller turbo the 3.94 seemes to give about the same time up your boost and the 3.55 starts pullin away

 

i was thinking of getting my 3.94 rebuilt and putting it back in my car.....but i should have my motor built within a month or so....so i think im gonna stick with the taller gears of the 3.55 thats in there now.....then i can have more fun with 15psi....