pulley is stock as far as i know, and nope it has 30psi, all the rest are 160-170psi, when i give it gas to pass if im under 4,000rpm the car boggs and my boost guage flutters around 10vac to 5 boost, like i have a vaccum leak, only way i can see a chipped piston dropping the compression that low is if an edge of the piston snapped off or the valves are burnt on the head