Um, i dont think youll be able to make enough power before you start overly stressing the chassis. They are strong, but not that strong......
Nicks turbo if he was psuhing 350bhp would about about there, still......it wont break it. The nova chassis used to split at the struts and inner wing when you had a 2ltr with about 170bhp pushing through it.
If you want an uprated(?) chassis, youll have to build one.