hello just have a couple of questions regarding the zetec engine in mk1 focus rs's , i no they have uprated internals over standard blacktops just wondering what there limit is would they withstand say 350-400bhp also it may be wrong but i read somewhere they've got forged pistons-rods , also remember reading somewhere that st170 heads flow better than standard rs ones aswell is this true?, sorry for the question just used to n/a engines .

thanks
nick