40psi

Thats not gonna last long, are you sure it's not a t4 even then that's a lot of boost and i'm not surprised it went tit's up.

For 450bhp mate it'd have to be a t4 i'd also check your intercooler as pace items are known to be not brilliant and at that pressure i'd be surprised if it was still ok.
Anyway if it was mine, 200 block with standard bore low comp pistons and wrc gasket.

oh and standard head bolts.

PJay