really depends on what RPM you are taking it to.
my car with 3.33 pulley non intercooled would see 5-6psi at 5000rpm, 8-9psi at 6000rpm. the 2.95 pulley non intercooled was 10psi at 5000rpm and 13psi at 5700rpm. during all this my tachometer was off, 6700rpm on the tach was actually only 6000rpm, and 6000rpm on the tach was 4800rpm. stock shift points with an auto are around 4600-4800rpm, so i thought i had a low boost issue for the longest time, when actually it was the stock shift points.
comparing npi boost readings to pi boost readings is a waste of time, their heads and intakes flow much more and at the same RPM make less boost, but most of the tachs in the 99+ cars are slow, meaning people shifting at 6000rpm on the factory tach are actually turning slightly more rpm, thus higher boost.
you need a smaller intercooler, with a GT/v6 front bumper there isnt much open area to get good airflow, so anything much bigger than the opening in the bumper is just adding restriction instead of adding cooling.
also the AFM boost pipe at your low boost level isnt going to make much if any difference, once you get an OD crank or smaller blower pulley the power pipe will help. the convoluted vortech inlet pipe isnt restricted much until 8-10psi.