The procedure starts with removing the valve
Rocker Arm cover followed by disassembling the Rocker Arm bolts for disposal and proceeding to remove the valve rocker arms together with the push rods. The first step involves removing both valve rocker arms and push rods from the parts. Prior to installation, the push rod and Rocker Arm friction surfaces require prelube gm p/n 12345501 (Canadian P/N 990404) or equivalent prelube product treatment. Note that intake valve push rods measure 144 mm (5.68 inch) in length with exhaust valve push rods being 152.5 mm (6.0 inch) in length. Install the push rods into their previous locations before applying
Camshaft and lifter prelube gm p/n 12345501 (Canadian P/N 992704) or an equivalent to the Rocker Arm friction surfaces. New valve Rocker Arm bolts should be installed before the users tighten them to a torque value of 32 nm (24 ft. Lbs.) followed by valve Rocker Arm cover reinstallation.