First i will use the thread to ask, then i will convert it into build thread ... as i cant find the 900rr engined zxr400 build, i want to ask what difficulties to expect with this engine, its 2003y cbr600rr bike, i can have the whole bike, its with frame problems ... but i can also use frame parts(to cut mountings and weld to my frame if needed ...) its my cousins bike, he dont want it anymore and offered me if i can put it into my zxr to give it to me for 0$

but i dont want he to send me the whole bike, as its alot money for shipping, so apart from engine with loom ecu etc ... what i can use, i read about the brakes ... are they better than zxr ones? wheels? i dont want to rebuild the honda, i already invested alot in my zxr400 ... not only money ... i broke 3-4 engines and i am tired of the 400cc engine, i dont plan to race it professionally, only for pleasure, its single seated, no lights, so its only fun bike ... i am not sure how good is the honda 600rr engine, but its what i can have for free, so if its possible to be done, i will soon convert this to build thread!
if you still think my thread is not for here, please put it where it should be ...