back from AMD now. It seems like AMD have in fact had their RR calibrated to give accurate figures.
Its confirmed mine does require an intercooler as the second run suffered heat soak again, so that is my next mod. happy with the output though, torque came in nice and early, with a nice plateau of power from 5k onwards.
shrak performance stage 1 rempa, stock everything else
from memory DomT made 320Hp 320Ibft, hedge made 248hp(i think), roberts 251hp 275Ibft, and the 5.7litre V8 corvette made................................................................
260Hp
but to be fair it sounded biblical