Kombi rear wheel bearing OD\'s

I'm looking to replace my beetle rear stub axles for kombi ones to match up with some rear disc/hubs got. Obviously the new stub axles are a larger diameter, which mean I've got to replace the wheel bearings as well - so, question is is the OD of the kombi rear bearings the same as the standard beetle, or does this swap mean I've also got to mod the trailing arms ?