Whats the best to use?

[charger90]

I bought a HRC kit for my 07 450ER. It came with the CDI box. Is there any difference between that and a Rev box? Will there be more RPMs with a rev box? Also I have a K&N (no lid) and a HMF slip on with the HRC kit, I'm looking for some more power. What the most cost effecient way to get this? And another question, will race fuel make a difference power wise as opposed to 93 octane?
i want my power to be good for the dunes. i was running a 14 tooth with my setup but my 13 seems a little better. what do u guys think about that as well.

[XXXRACER165]

The next step in performance for you buddy is to have your cylinder head ported, deff worth the money. Nothing besides a big bore kit, and porting the head, will gain you much more power. And if you go big bore, you will be running race gas as well. IMO you should of left the exhaust stock with the HRC core in it. It's as good or better than an aftermarket pipe, because Honda made the HRC kit to work together. I haven't seen 1 thats right not 1 person dyno a 2006 & up 450R with the HRC kit on here. Almost everyone thinks aftermarket makes more power than stock, they spend more money too. The HRC kit in itself "is the best bang for your buck". So yeah, have the head ported and it will be a monster.