what exactly does It need?

[250exDaniel]

I want to buy a used 400ex and I want to know what modifications the 400ex would need to beat or keep up with a raptor in a drag race.

I was thinking a 416 kit, or 440 kit, a WB complete system, k&n air filter and a k&n jet kit.

Any suggestions?

[R-Crazy]

with those bores you would want a hotter cam, high comp. piston, valve job, and maybe a port and polish, there is plenty more, but that is the basics. then you could do some damage to that crapter.

dave