Originally Posted by Jake99

Need some idea's here, trying to figure out my buddy's truck. 2004 5.3 scsb, had cam and full exhaust then I put a p1sc on it, it made 7psi with a 3.7 pulley. Changed to a 3.5, then to a 2.8, still only 7psi. Figured maybe the 108 LSA cam was a problem so I did milled 243s and 224/233 114 cam, still only 7psi. Made sence if the blower was maxed out, so we switch it out to a 12 rib belt drive with a f1r blower, has a 4.75 / 7.5 pulley combo on it now, went out and tryed it... Bam 7psi of boost. The recirculation valve was replaced with a big red pc bov, air to air is also replaced with a treadstone unit. What on earth could be regulating the boost to only 7psi? Next step will be to pull the intake rockers off a pressure test the entire cold side, just wanted to see if you guy's could think of anything else it could be before I did it. Thanks