my first harley was a 883 sporty, a year after i got it i tore the top end off and did the 1200 kit with buell pistons, buell thunder storm heads ported and polished, andrews n8 cams and a se 1200 ignition. put the bike on the dyno and it made 87hp and 80lb tq and still payed 883 ins rate. cams and heads are both different from 883-1200 but cylnders can be bored to 1200.