urgent!! diff question

[tickle]

can anyone tell me if this is lsd

3,9.1 011

im looking at replacing my 4,27 diff on my 318i m10 engine.

is it a straight swap, (i.e adjust prop + go) and roughly how much accel loss + speed gain

i dont want to sacrafice sideways capability and torque, but ive been told the 3.91 is far better anyhow? also the driveshaft joints seperated so will i need a new seal? and is condition easy to check as it seems a little stiff?

need to fit it later today sorry to rush, any advise welcome

[Brianmoooore]

Nothing in that number to suggest a LSD. There should be a "S" on the metal tag for a LSD.
Diff is a straight swap. Both small case and medium case diffs fit without any change of other parts, although the preload should be adjusted near the prop centre bearing after any diff change.
Part the driveshafts at the ring of torx or hex bolts at the drive flanges on the sides of the diff.
Don't let the driveshafts fall when you dissconnect them - you may damage the outer CV joints.

[tickle]

thanks for the help