Do the rear bump stops just twist off on a ea82? I can feel a nut on the backside of the body mount, but don't want to go wrenching on them without knowing. 

 

I want to fab up mounts for some heavy duty ones. 

Should twist out. That nut is welded as I recall. 

big plate nut about 60 odd mm has a threaded stud about M10 that threads into the captive nut inside chassis. No twist off about these mongrels. Hardly any purchase on the sheet metal nut about 3 mm thick. The plate has big surface area to crud up and stick tight, then the chance of the threads being corroded... fortunately the sedans did not have these, just in-built bump stops on the rear shock struts