Hey Rich,
My GTR initially had an Apexi IHI RX-6 TCW77P25. Stock RB26 with a couple of cams. Little baby, could only make 400hp atw no matter how much boost I threw at it. left it on 19psi, super responsive, full boost well under 4k ran heaps of mid 11s at the drags. (ps if anyone wants it - it's sat in the garage at home with manifold, wastegate setup etc). Upgraded to a GT35R and overcame the tempation to go to the T04z and the like. Useable power > *
A new GTX3076 or whatever they are would be wicked.
Mick