Definitely 750, brought another set of cyls and pistons to Jims workshop when we first decompressed the motor in August, just in case it had previously been oversized.
its actually a 99, very much like a little busa, removable cyls and efi were the main reason for picking this model to build and not a later bike.
don't know how much hp all tuned with a logger , but have a gt28r on it pushing 27 psi (couldn't get any more at that altitude )
Myself, FiremanJim and Mick (who has a turbo 750 here in Aus)