Yes, you need to buy all 3 parts. It remains to be seen whether the solid rotor core is better. Even if it is, it's possible that the "new" rotor head might not be as good as the stock. Of course, this whole discussion comes out of the fact that a LOT of people end up breaking a LOT of rotor cores so it seems like it would be worth a try. I'm still pretty good at crashing so I should be able to give you an opinion in a relatively short period of time. I also have plenty of the spare stock assemblies to go back to.

Bill