i have a few diffs but only 1 nice 1. its a 3.91:1 LSD. is it possible to modify it using other parts from diffs to get a lower ratio. say 2.8:1 or 3.5:1 and what would i need to change? my engine has nice power at 12psi but first gear is waaayy too short and my top speed is limited to about 140. i would like a 160-180mph limit i i cant modify it what ratio do you think id need to teg to that top speed? i also have a 325i sport gearbox. im not sure if that makes a difference. and just 1 more thing. the clock only shows a max of 150mph. is there a way to change it to 1 that has a higher top speed? thanksThanks in advance