Best I can tell, according to the Buell.com links in my 2nd post: the engine VIN you posted points to an '05 Lightning 1203cc engine.
But I'm not sure why the engine VIN you posted doesn't have a 4MZ or 5MZ before the number unless that's a motor off a true HD Sportster. (4 or 5 means domestic or not, MZ means Buell) Maybe BPG will weigh in.
