700HP-GTR33 I certainly hope you're kidding around because thats a ridiculous suggestion that unless they have 2 turbos, a GTR is not a GTR!!
Have a look next track day and see how (especially a certain) big single GTRs go. The days of useless BFOTs has passed, there is absolutely no reason a single can't do what twins do.
Back on topic T78 is way too BFOT, T04Z is awesome in comparison, 500rwhp @ 19psi with delivery by 4500rpm not being strictly on/off either, with the .81 rear. I'd track back towards something like a GT3037, GT3040 for the lower power level.