why do you want one? how can you be running that much boost and not knock? the m90 gets so enormously inefficient and heat producing past a 2.8 pulley that it would be stupid to run that much. get more flow mods before you run a smaller pulley. you dont want more boost.
why dont people get that boost is a measure of restriction. hell, if i could stay at the same power level and have enough flow mods to run 5 pounds of boost i would do it.