Just found that article from HPP, here is one paragraph:
The bypass-valve ball and sealing surface of its Pro-Series oil pump are machined and blueprinted. “The bypass spring is tested to ensure consistency, and pressure is set to 75-80 psi at the gauge—though depending upon bearing clearance, it could be higher within the engine. We can shim the pressure relief spring to increase pressure slightly, or install a 60-psi assembly to reduce pressure, depending upon the engine’s needs. The finished pump is completely tested and includes a detailed flow chart,” Butler adds
Read more:
http://www.highperformancepontiac.co...#ixzz1egYccjVO
I am deffinatily contacting Butler and see what thy say.