vacuum prob
 

hi guys have a question about my 7mgte i have aftermarket turbo/62-trim turbonetics turbo with brian crower 264/220 cams and i have low vacuum at idle like -6 to -7 psi and from what i have found it shows stock should be like -15to-20 at idle. i know bigger cams can bring it down but not that much right and the other question is when they say psi is that standard psi or hg/psi cuz there is a big diff and im not sure what one they r referring to with the stock numbers that i have found it all just says psi?