anyone done it? i have a 3.9 vlsd from a 91 leg(yep with stub shafts) and a 4.11 in my obs. im going to atempt the swap just like the 3.7-3.9 swap... anyone ever gone 3.9-4.11?????? thanks for any info....

it should be the same as the 3.7 to 3.9 swap, just with different gears. just dont forget to change your front diff as well..... meaning you will have to swap trannies....

Let us know how it goes i am thinking of doing it.

Wouldn't an OBS have the newer style rear axles where the inner DOJ has a stub shaft that's machined out of the same chunk of material? There may or may not be an issue with getting those to insert correctly into a VLSD. If there is an issue, you could probably use the stub shafts that came with the VLSD and use some rear axles from an earlier Impreza.

Just use the ring/pinion from your old diff on the new diff and you wont have to change anything else.

 

I've got a 3.9 VLSD WRX diff on my 4.11 RS tranny in my L via that method.

should work fine, just keep the side case shims matched to their associated ring and pinion, I mixed them up on my 4.11 clutch type LSD swap and the diff slowly ate itself up in 10K miles.