I have alredy installed a R200a front diff with a LSD centre in the front ( that was a bit of a mission sourcing parts to make it all work) and am currently soucing another transfer case, as it sounds like my chain is slipping. I hear that the d21's have a wider chain but from what i can see, have a diffirent splined input shaft and seems to be quite the hassle to make it work. Had anyone succefully upgraded their transfer case to the one with the wider chain or just keep using d22 spec'd ones?