To make things simple one must understand that no Ironhead Sportster is like a brand new bike. Many bikers buy one because they can afford it. They also stay away from brand new parts. Some get repair manuals and learn which parts are enterchangable. They then can find some used parts to use. That allowed me to get a 1971 drag bike frame. My 1980 1000cc engine fits in it fine. Just had to do some welding on the 1980 swing arm so side bolt on short shovel head shocks could make the bike sit lower than it had while stock.