Hi teza, hope there's nothing big wrong with your 4.2. Keen to hear how things go, so please post an update when you can. There uesed to be a 4x4 dyno guy at Big Country 4x4 Accessories, 204 Creswick Road in the centre of Ballarat on the right side of the Midland Hwy facing north 5331 2113. As nissannewby said above, boost should not be more than 12 psi & with sensible (correct) fueling, if you are running standard size tyres, should get about 85-90kw. Dynos do vary in readings. Is your exhaust Nissan standard or have you fitted a larger one?
Cheers