OK, got a Quaife put in a 3.27 diff here is the reply on putting it in.

No problems fitting the Quaife LSD, only that the inside of the housing had to be ground a little bit so that you can get the LSD/crownwheel assembly back in. Any differential building shop should be comfortable with that inlcuding any Quaife dealers in the States.
What problems have they been having? I've heard of true-trac but don't really know what it is to be honest.
The only issue with ordering one for your 3.07 diff is knowing what Quaife part number you will need... I take it it's different to the one we've just done for you? We have about 20 variations of Quaife LSD for Mercedes models so I'm confident we'll have the right one!
Thanks, James
James works at KEVIN BIRD GARAGE (UK) who put in my LSD, they have shops in the USA. i should have it in a few weeks and will get it installed, i hope to get to Tail of the Dragon so I can see how it helps.