carb change over need help

[465dragbike]

I have 2000 400ex and it has a stock carb right now. I'm boring it to a 465 and need a different carb. So I'm looking at getting a crf 450 or a 450r 06+ carb. Which would be best and how do I get them to fit on my ex?

[kt1148]

http://www.atvriders.com/vbb/showthread.php?314423-My-450R-carb-installation&s=&perpage=13&highlight=carb

[Atvers]

Just an opinion how about getting an aftermarket carb like FCR? I guess that would be more efficient.