Lifter adjustment- I like to adjust them warm and running.
In your case, it sounds like the lifter is dirty or the hard face is worn off the cam. Smoke out the exhaust may be rings or valve guides.
To adjust a chevy V-8, first determine which side of the engine is clicking. Remove the valve cover and start engine. ( engine should be just a little bit warm and off choke) Using an old heater hose, listen to determine which lifter is noisy and note position. Using the 3/8 drive and socket, tighten adjusting nut while engine is running slowly. while listening to click.It should almost disapppear. Oil will drip on your manifold and make smoke, so move quickly.
If the engine labors too much , you are getting too tight. My favorite trick is to tighten till click just goes away, shut off engine and then turn 1/3 turn more. Then reassemble. If you are adjusting all of one side, it saves lots of time. If you have trouble determining which is clicking, use the hose to listen to each one as you adjust it.
Good luck with your Chevy project.
I have a 87 Iroc Z28 305, 73 Corvette 350, 69 Nova SS427 and a supercharged 400 40 Ford Pickup.
