Dumb question - difference between Dodge and Plymouth

Not much difference in the run of the mill Mopars from what I understand. Urban legend says that the Hemi's, 6 Pack's and the TA engines were hand assembled. I also heard that the Chrysler's were hand assembled too. I have never seen any fact to back any of those legends though. The strange thing is that the factory used under and over sized bearings and pistons to make up for production tolerances and have bearing clearances in spec. I would there was a bit of hand assembly involved there.