If he does nothing more than headers, his INDICATED boost will be lower. This is desirable, as it shows the engine is flowing properly. Boost pressue, as indicated by the boost gauge, is boost that is NOT being used. You need to increase the CFM'* flowing through the engine to make the most of it.
If you decrease pulley size, your indicated boost will increase. But it may induce KR. At that point, you install Ported Exhaust Manifolds, headers, rockers, or a cam to combat the KR. Your boost indicated will then decrease slightly. It'* a game. Mod, get KR, kill KR, mod, get KR, kill KR.
In the long run, it'* FLOW RATE that matters, not boost PSI.
There are some good articles in Techinfo (link at the top of the page) to get you started, and the two primary performance vendors are www.intense-racing.com
, but there is also www.grandprixstore.com
, PulleyBoys, thrasher, DHP, W-body Store, and a few others.
Keep in mind that just about anything for the engine is the same as the Grand Prix, and don't mess with the exhaust until you hit the 13'* on the quarter mile.