The GTiR blocks were designed to be used in BTCC and JTCC where they bored them to 88mm and used a 82mm crank which was 1995cc's.
I know the GTiR blocks were cast with the liners thick enough to reliably do a 88mm bore. I would imagine the std blocks all use the same liners and 88mm would be ok as well.
I have done 2 87.5mm turbo builds before. both about 475whp