crf450 motor in a 250r

[PeanutButta]

hey i have a 1987 trx250r. im looking for a crf450 motor. but im wondering will the 450 motor fit in the r frame. if it fits is it gonna be hard to put in like a tight fit. also with the 450 motor in it ur gonna have to use a crf450 radiator then to right or can u use the r's radiator.

thanks

[stocktires]

No, it wont fit without major hacking. But yes, you can use the R radiator, but it really wouldn't be efficient enough...
Use a yz426f motor and an aftermarket radiator...