Valve Adjustment '99 5.7 vortec.

1999 burb 5.7L 4x4 Vortec with 130,000 miles. I Have been hearing some valve noise starting. Was wondering if anyone has attemped to set valve on one? Does the a/c braket have to removed to set valves? and if so, with the braket removed how do you keep the engine running with no accessory belt? Is it worth the trouble? Some people say it makes a noticable difference in power/ engine smoothness. Thanks for the help.

The valves are not adjustable.
But if a valve lifter noise check rocker arms and push rods for wear and or for a rocker nut backed off.
Also for a broken valve spring.
When do you hear the noise?
Start up or cold or hot or all of the time?
Just one side ot both?
Good clean oil and AC Delco oil filter?

It makes the noise when at operating temperature and idleing. I suspect maybe one if the rocker nuts has backed off. The oil is changed regularly and have been using fam oil filters. Thanks,