Camshaft, Lifters and Push Rods: Service Precautions
CAUTION
^ After installing the camshaft(s), the engine may not be started for approximately 30 minutes. The hydraulic adjusting elements must seat themselves (otherwise the valves will strike the pistons).
^ After working on the valvetrain and lifters, carefully rotate the crankshaft by hand at least 2 full revolutions before starting to be sure that valves do not strike the pistons.