To find the correct torque specification, you MUST consult your vehicle's repair manual or a reliable source like a GM service manual specific to your 1999 350 Vortec engine. These manuals will list the torque specifications for each individual bolt based on its size. Using the wrong torque can lead to stripped threads or a loose bolt, causing serious engine damage.
Attempting to guess based on generic torque values is extremely risky and could damage your engine. A repair manual is the only safe way to proceed.