Rolls, if I can find Legend01's dyno of his RB20 you might have a bit of a rethink.
Found the link to the UAS dyno chart making +270rwkw , couldn't find the 300rwkw one which is somewhere in the NSW section (from memory).
http://www.skylinesaustralia.com/forums/topic/58229-top-rb20-club-do-you-have-over-260rwkw/page__view__findpost__p__3129315