engine set up

I am looking at the vortech s-trim. right now I am confused. I look on the website of vortech and they say that the s-trim can handle 20 psi. I am looking in summit and they offer the s-trim set up that runs 8-10 psi. If I order the kit from summit, is it just the matter of swapping pullies? Can someone help me out?
Thanks
 
its just a matter or swapping pullies, spinning the hell out of it, and having a poor flowing motor, and youll see 20psi on the guage, and your crank in the rear veiw mirror. An S-trim is an S-trim. The pully it comes wth from summit can be changed out for more or less boost. You can find many cheaper deals via the internet if you look around. Check out www.corral.net/forums "Power Adder" Classifides section for sales and deals.