350x axle

[DJR300ex]

will 300ex hubs fit on a 350x axle?

[enduro400rider]

no

[DJR300ex]

ok thanks. will a 400ex axle fit a 300?

[enduro400rider]

not really, it will but you need to make some custom spacers and what not. your best bet is to go with a 350x axle, thats what i did. it supposed to bolt right up, with a small spacer between the lock nut and carrier, 250r hubs will work with a 350x axle, but i beleive you need spacers if you run R hubs, or at least thats what it looks like to me, im in the process of fitting a 350x axle in my 300, using R hubs.