Thanks all, for your responses and advice... much appreciated.
I'm really tempted to go down the GT30R BB path as some of you have suggested, or even perhaps the Precision Turbo route, which would certainly be cheaper than the GT BB.
I'm told, with the 3.2 motor, I can just do a quick top end job and fit some C2T head gaskets to lower compression to around 8.8:1 and then I can safely run 0.85bar for approximately 485HP.
Have any of you done this mod? If so, how well does it work/perform?
(3.3, Protomotive MAP ECU, EFI, GT2 EVO CAMs, Twin Plugged, Twin Turbo's)