Sigh My dad has a 450 fitted with a raised saddle and riser bars and what not to make it work nicely for him and he's 6' tall. It feels good when I get on his bike but I still need some more so I don't have to work so hard to to get my ass off the saddle.

I haven't ridden a more powerful bike and they seem scary. Have you thought of doing so other kind of racing like Enduro rather then MX?