when my car was a aode i had 3.90's in it and i had a girlfriend that lived 50 miles away...now my new girlfriend lives up the street but i sold my 3.90's to get 3.55's. well now that im a 5 speed i was wondering how different it would feel to have 3.90's? are they more for a auto or should i invest in them again? i can install them so labor isnt a problem, does anybody have them? how much different do they feel on a 5 speed? are they bad on the highway? gtr high performance told me to stick with the 3.55's because i wouldnt like the way the 3.90's felt