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OK, Time for some tech, even if it means I to take apart a perfectly good (almost) engine.

I got a tic.
Not just a tic, a TIC!!!

It sounds like a very loose rocker. just one, not more than one. It only happens on cold start. I hear it mostly when she's revved up a lil, not so much at idle. It goes away within a minute. When it goes away, it just stops making the noise in an instant.

Cam is a lunati billet hydraulic roller, 231/239 @ .050, .530/.550 lift on 110. Lifters are Morel.
It's been like this since the cam/lifter/whole valvetrain/heads were new. I've readjusted the rockers several times, including with the engine running. Hot they are perfect. I've tried zero lash plus a half, plus 3/4, even plus a full turn. Made no difference on the cold start noise.

This has been happening for 3 years, 5 or 6000 miles. Car runs great otherwise. I don't even know which one is making the noise.

What would you do?

Well Jim since you are going for perfection and considering all else you've done I would pull and thoroughly clean all of your pushrods. I'm thinking some minor blockage that does not matter as the oil heats up and thins. JMHO

"Busy work" Don?

How bout a way to pin down which one is making the noise?

Problem is, I only hear it stone cold, and it's hard to hear at idle.
I really don't want to pull the valve covers and rev her to 2 grand, I'll be cleaning oil off the walls of the garage and everything else!

Change to GM lifters.

Sounds like an emergency Team Camaro SS meeting with cold beverages at Jim place is the best way to handle this problem

Conference call?

I have a mechanics stethoscope I can bring Wed. Maybe you could cut the top off a junk valve cover and tape plastic over it. Then have Carol start her while you watch.

Good advice Don. I thiink the stethescope and the old valve cover are your best bet. We had a VC with the center cut out when I was a mechanic to adjust valves running, worked real good on hydralics and kept the engine clean. I doubt the problem is dirty pushrods as I believe the noise is fom the lifter not the top end.

Should be easy enough to narrow it down to what side(bank 1 or bank 2). Pull that cover, check to see if there are any suspicious ones(loose), spin the motor over some to check all of them at the base of the lobes. If you don't see anything that would indicate a possible failure then just readjust all the rockers. Sometimes they just loosen up a tad even with poly locks.

Keep the ideas coming guys.

First thing is to narrow it down to "which one."

I personally think it's a sticky plunger in one of the hydraulic roller lifers, maybe a burr or something, or a bad internal valve?
Problem has existed from day one with this valvetrain.
The really eerie thing is the way it just stops. One second it ticing to beat the band, the next it is dead silent.

"Way back when" I've tried silly things like taking a valve cover off and putting a long extension against the top of the polylock and sticking my ear on it, but I've never been successful in even determining what side the problem is on.

Maybe I'll try again today.