Not all R180 diffs were created equal, the later ones had thicker stub axles, a very desireable feature. Don't ask me to define 'later' because apparently in this area what the US got was not always the same as elsewhere.
All I can say is that before removing the R200 and going with a ATB R180 using the skinnier 4wd stubs, after doing the research I was happy to do the change, anticipating up to 280 rwhp and turbo torque once the goodies were screwed up.
But thats with a rolling start, no clutch dumping which kills transmissions.