During my cam installation, I reused the original valve locks with new springs, seats, seals, and retainers. Upon starting the engine up, I heard a clicking sound that I only just identified. After tearing down the entire valvetrain, I found that one of the two locks on the #8 cylinder intake valve stem were missing, and the other was cracked in half and just barely hanging on.
Obviously, I'm relieved that I caught the problem in the nick of time, but this is my daily driver and none of the shops in my area have replacement locks in stock.
During the diagnosis of the problem, I also found that my #6 cylinder was not providing power by disconnecting and reconnecting the ignition coil attached to the #6 spark plug. Is it possible that the missing valve lock half somehow got into that cylinder or jammed the lifter? There's a lot of space behind the top of the heads that the lock could be hiding in, but short of removing the heads, I won't know.
I've identified that Comp Cams #623-16 is the correct lock for my LS2 application. While I'm at it, do you think it's worthwhile to replace all of the locks in the valvetrain? I think that this might've been an isolated incident due to installer (namely, me) error in setting these locks in the retainer, but maybe this is something that happens with stiffer springs (in this case, Comp 26926 with 470 lbs open seat pressure).
EDIT / Question #3:
Ordered 16 new Comp cams locks. In the meantime, do you think I should be taking off that head to ensure that there's nothing down there? I did a visual inspection with a flashlight--even peered down the pushrod holes--but couldn't spot anything.