Faster spoolup but shorter top. Noise from mine is most annoying around 60-65, 75+ is barely audible. Very goeod for street driving, car is more responsive, that's for sure. I might ditch em after doing the 2.5 ic/intake but will have to see. That's the beauty of it- swap the diff out and you are good. Just need to change the speed pinion otherwise the reported speed will be higher than actual.