Stock boost is 9psi and the limit is 12psi with the secondary boost control. Once it see's higher boost than that it will open the by-pass and bleed off the excess boost. If you run a pulley to get higher than 12psi you must have a tune or it will just keep bleeding off the pressure. You also have to pull the vacuum line off the "P" valve and cap it so you can make over 12psi without it bleeding. But even running boost below 12psi it would be best to let a tuner write a tune to optimize the additional air volume because it affects the fuel tables. But yes...the ECM with a proper tune can handle the AF adjustments fine. Its the fuel system that will become a problem once high horsepower levels are reached. Some tuners have already figured out those limits and developed packages to handle the issues.
