a t34.48 will never in a million years make 400bhp.....i had a dam good spec engine at 32psi from one at 380bhp, it had absolutly nothing more to give....i tried. and turbos were lasting 6 months at this level.

a t34 .63 can make 400 just.

i did make 400lb/ft with the .48 though and broke standard boxes like chocolate

as for cr...std, or 7.5, i wouldnt go less at that spec