When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
According to the service manual, the pressure for an LS motor should be 39.8-46.9 psi and the pressure of the GSR motor should be 47.6-54.7 psi. This is measured with the vacuum hose disconnected and pinched.