You can actually hear the chains on the 88B. What's worse, there is for lack of a better term, a laggy feeling to the 88B compared to the 88. It's led to a lot of veteran bikers tearing up perfectly good carburators thinking it's a jetting problem.
I always thought that noise was just an inherent timing chain noise because of the twin cams.
Hall of engines link all the way back to knuckleheads
http://www.harley-davidson.com/EX/KNO/H101/en/hallofengines.asp?locale=en_US&bmLocale=en_US&WebLogicSession=A9Wg2ZXAKyv3xIy2tiErXvzoLZZQtT6l46sIjhOJ6C452wN7qe23!-1636602063!181237813!7005!8005