So, as I understand it, the NA LSD from a s4 will work in s3 gsl or gsl-se rears. I am wondering if anyone here has undertaken such an endeavor.
The reason I ask is, I want to buy a Kaaz LSD unit for a s4 NA and use it in my 84 GSL. AND I want it to go in without problems.
I have found some info about swapping Miata torsen rears into 1st gens and the guy had problems with the axle shafts seating all the way. Had to move the wheelbearing spacers and do other mods to the rotor and studs. I am wondering if there are similar problems with the s4 LSD units.

 

In my research, I found that you only lose 10mm of spline contact. So long as you're not putting down 300 HP you shouldn't need to do all that.

If you are worried about it, Moser engineering sells replacement Axle shafts that have been lengthened for $300 a pair. They're also stronger which'd probably help if you're putting down 300 HP...

Additionally, I'm trying to contact someone who can speak Australian and has contact with Guru Motorsports. They sell a floating Hub/axle replacement kit that I'd like adapted for this purpose (And to have the SE bolt pattern and offset... On the site, they advertize 110x4 PCD...) Rob from Pineapple racing still has as of yet to return my e-mail...

 

Actually, right after I posted I found that info about Moser`s custom axles. Thinking about custom shafts, though. It would be nice to get a 2nd gen 5lug bolt pattern out of the deal...
Now that you mention it, I remember seeing Guru`s floating axle deal some time back. I think it`s $1200 or so?