ok so the car is bone stock as of now, and I would like to replace the supercharger thats on it now with a vortech. I need to know how much boost it will take.

Vortec is not a forced air induction system. It'* a type of intake system. Kinda like Hemi.
If you want, your more than welcome to take a Vortec 4.3 and drop it in. Just make sure you take lots of pics.

Mike...Vortec is also a brand/kit of supercharger. They make a kit that would bolt right onto my 5.3L Silverado.

The stock gaskets etc are rated for 10psi. Many people have easily and continually pushed 13-15 psi without a problem. I know adapters have been made out of intercoolers for the MP112 and other chargers, don't think I've ever seen a Vortec adapted. But as long as things are relatively the same as some of the other chargers....it should be possible.

One issue you will run into is supporting mods. Our front exhaust manifold, heads and cam are all restrictive on the motor. While having the boost number is nice..it'* not much more than excess pressure stacked in the intake manifold. To be useful, it needs to be flowing through the heads and out the exhaust pipes.

My bad, I thought he mispelled "VORTEC" and assumed he was talking about the other system. I'll exit stage left now....

Actually..I misspelled it.

I realise that the heads cam and manifold are all restrictive, but changing the super is a much more expencive mod so i would like to get it out of the way wile i still have the extra cash to do so. I was thinking about using a vortech v-9 because of the space or lack of that i have to work with. i was thinking about running 12lbs to start but if what you say is true then i think i'll dile it back to 8 or 9 to start out. also for future reference it is a 99 ssei

why not save yourself alot of time, money, and headache and simply get a generation III M90 that is ported, polished, and has a smaller pulley?

seems like the more logical solution since it bolts right on?

All you have to do is change the pulley.... more boost at a cheap price.... you can run the current supercharger up to 12-13psi..... if you have the supporting mods of course..