Lol!!!!!!! $3,900??? Hahahaha, sorry man. i love the fb but that is some fuckin crazy pricing! i had a fb with a racingbeat intake and holy 650 and it was even painted, but i still didnt think it was worth that much. AND if the engine is not ported, the 650 is too big for it, they recomend a 450 or so with factory porting.