Stereo types aside, I used to enjoy an E46 M3 with around 330BHP and it was a TRUE everyday super car! REALLY nice diff too when pressed hard but I believe it was a clutch based one (but then there was quite a lot of electronic interference to keep it on the road too).
Now back to diffs for Zs, the scooby swap needs to be a 2007-2015 model for it to be an ATB Torsen version. I believe they only come in 3.54 final drives.
At around £400-£500 for a decent one + cost of stubs (£370ish by the time tax and postage take their toll) it's really not that far off the Quaife, so is it worth it? For the £700 initial outlay and a couple of hundred-ish to get it built, you may as well have something new and bullet proof.
Reading club archives, i understand my late 260z was supposed to have a 3.7.
Is there a definitive (Albrecht?) list that shows what diffs our European cars were supposed to have as standard by year?