@ Azerp
I wouldn't bother risking more power runs,
You have a dyno readout saying 337bhp, so as far as anyone is concerned, that's what she is! be happy,
Even less 5% is still 320bp which is acheivable on the Vf23
I would defo look in to getting her map checked, she is obviously mapped to her max on jap fuel! engine is to nice melt!
Dan