The technology from old harleys to new ones is hardly even similar just one of the many major differecnces is the cam shafts the new cams are completely different they are made to give the same sound that harley is famous for however once the bike isn't idling the similarities end, I work on the 94 heritage and made some changes to the 07 fat boy of his and even that close age wise the technology is extremely different the new bike is basically made to sound and acted similar while being more reliable so it seems the same until you start working on them and then it's night and day