Diff mix up

[Mr Deagle]

it will bolt right up, dont worry

edit: dont do burnouts or you will blow the small case diff up

[MikeE30325i]

maybe all of them. depends on how less wide the diff is

[smonkbmw]

the driveline from the trans to the diff? or the shafts from the diff to the wheels?

[MikeE30325i]

i believe it would be a longer driveshaft, or pay a shop to extend your slightly.

[smonkbmw]

i have a 89 325i.

i bought a 3.91lsd diff from a 84 318. ive been told its not going to fit? something about the drive shafts being to short because the 318 is a small case diff and the stock 3.73 is a medium case?

what do i need to get the 3.91 to fit? i heard all that i need is the driveshafts? help!