what's involved in a differential swap??
 

I'm getting my 1999 996 C4 back on the road and was thinking about taking the Guard torsen diff from my Boxster S 6-speed and swapping it into the 996 trans. I know that I need to keep the 996 ring gear mated with the original pinion. I'm wondering what's involved with the diff swap. I've done diff swaps in a Chevy rear where there was lots of assembly/dis-assembly to get thing shimmed right for the gear lash. How about for the Porsche Getrag trans??

Same I believe...there are tons of different thickness shims to set up backlash. I believe you take the nose casing off and mount a dti in there to measure it..not sure how exactly

I just got a 996 LSD to fit my box s. Didn't know about the need to keep the ring gear

My understanding is the 996 trans is very similar to the 986 six speed. The diff bolts to the ring gear and if you use the same shims when you re assemble it, it should work. My indi rebuilt the lsd in my box. When he opened it up he could tell by the wear pattern on the R & P the factory shims where not dead on. He used the old tried and true paint and test to get it right. No need to get into the gear stack to do this.