Just wanted to pass along some results that I had.
The car is a 97 Z28 M6, 150K full bolt on stock internal.
A few months ago I noticed the car hesitating and missing at around 5-6K RPM.
So with the car at that mileage I decided it was time to replace/upgrade some parts. I had already done 1.6 RR, Hotcam springs, hardened pushrods at 90k. The RRs made it noticeably louder, you all know the ticking sound Im talking about. I adjusted the RRs at 1/4 turn past 0 lash, locked down the set screw and gave it another 1/4 turn. Ive always done it that way, and have had good results. It was a bit loud, but no louder that countless other LT1s with RRs Ive heard, some stock cammed others aftermarket.
Ok, so after I noticed the miss, I parked it and it sat for a little over 2 months while I gathered some parts. Comp 918s, new TR55s, Taylor OVC cut to fit wires, comp rocker arm studs and polylocks, and a racetronix 255 kit.
After all the parts came in I went out and installed everything. Adjusted the RRs the same way Ive always done it. 1 cylinder at a time, with the engine not having been ran in over 2 months. I turn the key, and it starts right up on the 2nd crank. I let it run for a while keeping an eye on everything, let it get up to temp everything seems ok. Ive driven it for a couple weeks now and it runs great. However, the valvetrain is very quite now, like stock almost, you cant hear anything from inside the car. Havent had to readjust anything.
My guess the reason for this is the new rocker arm studs. Ive noticed several people complaining about loud RRs, so I just wanted to pass along that info.
Sorry for the long post