Hard to believe but..
Alot of people may say you need to open up the exhaust, dont let that scare ya, i used to max out at 12.5 psi of boots and after removing the resonator and chopping the mufflers (sounds like an indy car) i list 2.5 psi of boost. what im trying to say it it is fairly easy to drop enough psi to run a smaller pulley. If its a post 93 SC i would just run the 5% as the blowers on 94's and up were more efficient