01 mustang gt questions

[johns01gt]

i have a 2001 mustang gt that i bought with some modifications. i'm trying to see what kind of rear end comes factory in it. is it a 8.8 or a 7.5? also what type of fluid do i need to put back in it? and i was told it has 4:10 gears in it but im not sure. so how can i tell?

[PureVenom]

What RPMs are you at at say 55 or 70 mph?

And, it comes with an 8.8" rear end stock with 3.27 gears.

[johns01gt]

it sits at alittle over 2000

[johns01gt]

at 70 aroun 2500

[Cobra GT]

If you are changing the oil anyway you can pull the diff cover and count your ring gear teeth and your pinion teeth and divide them to get you your gear ratio, as for the replacement oil I would use Ford oil, it probably has friction modifiers that your limited slip diff needs.

[sweet2kstang]

8.8 stock
sounds like you have 3.73's (4.10's will be 3k rpm's at 80mph)
80-90 fluid and make sure the fluid has friction modifieer or you add it in