Hmmm, I wonder what your doing wrong this guy here claims he made 730rwhp on only 24psi 18* of timing, smaller 6567 billet wheels precision turbo, stock GN1 heads out of the box and smaller 212/212 hydraulic roller cam, he posted his combo too so everyone could read it and also posted dyno runs, of course he had XFI tuned by Cal but i doubt that will make that much of a difference.
http://www.turbobuick.com/forums/time-slip-combo-database/345289-how-much-hp-will-make.html
Boy you're a hater. Here's another stock stroke motor making 700+ with an ECM none the less. Guess you just have a turd.