which motor is taller 426 or crf 450

[QuAdEr 317]

i am looking to buy a quad that has a 250r lsr frame converted by eastcoast atv for a yz 426 motor...if i was to get this quad i would take the motor out and sell it for a crf 450 motor. i heard that a crf motor is to tall for a 250r frame but if this is converted for a yz motor would the crf fit?..i no a yz motor is also taller then a R motor also.. or if you could just tell me how much taller one motor is from the other or if they are basically the same? thanks

[R3Concepts]

I think the Yz motor is quite a bit taller becuase I know a guy that had to cut the top rails off his 250r frame then fab some in over the motor. I would go with the crf450 anyway, cant beat hondas.