You are not supposed to, it has hydraulic valve lifters, but if you think you need to, start yur engine with the valve covers off, at idle tighten each rocker arm bolt until they dont make the clicking noise.
If you have roller rockers (aftermerket), wait until the engine is dead cold, then get a feeler gage, the thickness of the feeler is the thickness of the oil film, s it must be .25mm at the most (check the specs of your roller rockers).
how do you set valve on 1998 350 vortec
Stock 350's have hydraulic lifters, so feeler gauges aren't needed. Get yourself a Chilton's manual or similar and read up on the valve adjustment process.
.003 on intake and exhaust
they are either too loose or worn out
It has hydraulic lifters, no adjustment. If you have valve noise you probably have worn valve train parts. Replacement of worn parts would be required.
No adjustment.
No adjustment. If there is valve clatter, valve train parts are worn.
5.7 later valve adjustment procedure begins with the removal of the valve cover. Each valve has an adjustment screw. The screws can be turned to adjust the valves.
There is no valve adjustment for that engine. If you have valve clatter you must have worn valve train parts.
I would be suprised if you have adjustable valves.
ValVe adjustment on 1997 oldsmobile cuttlass 3.1
No adjustment required. If you have a noisy valve train, parts are worn.