HKS 2540, as paulr33 said, a bad choice. Search around for older threads and you will see.
It is capable of those figures, maybe a touch higher, but the usable power is right at the end of the rev range.
Robbo (i think, maybe robbo33) went from a HKS2530 to 2535 on the RB25 and seemed to like it.
He has since gone up again but check some of his threads and maybe flick a PM.