crf450 quad, how much work with a 400ex frame

[johnnydufus]

how much work would it be to put a crf450 engine inside a stock 400ex frame? cuz i have been reading about how people got a yfz450 and has alot more power over the old 400ex's. and i was wondering "when" i get tired of the power if i could easily drop a crf450 engine in it

[redrider05]

its jus not a simple drop in.....u need to send it somewhere that does these conversions...i sent mine to jb racing n got A+ quality from it.....the crf will pull nething out there easily.....i am also selling my crf n chassis if interested

[johnnydufus]

where did you get your 450 engine?

[nosliw]

http://www.exriders.com/vbb/showthread.php?s=&threadid=90605&highlight=400ex+conversion