Hi there Guys:
I know this is a really, really old thread, but here it goes:
Yamaha nor honda changed splines to fit another.
Honda's 83-84 ATC 250R, ATC 200X, 250EX, 300EX, 400EX and 450R
will all fit the Banshees, Blasters and 660's.
That said All the TRX's hubs will add 2.5" to your Yammie rides. And yes the 250EX, 300EX, 400EX and 450R are all the same rear hub and part #. These are all 24 spline rear hubs. Some other Honda's use 25 splines, like 85-89 Honda ATC's and TRX R's. Also, and very important, the hub should be an old one so it's got a bit wear on it, that's the only way it will fit without having to hammer on it too much. The hubs are design to wear first than the splines on your axles, so finding some with a bit of wear is not a problem. By the way Hondas are 4X110mm wheel pattern (most of the ones talked about here anyway).
Just thought I clear this for you guys. Don't ask me how I know. Been around since before banshees and quads in general were new.
And yes, this is my 1st post.
TORKER.